review of related literature and studies description

Have a language expert improve your writing

Run a free plagiarism check in 10 minutes, automatically generate references for free.

• Knowledge Base
• Dissertation
• What is a Literature Review? | Guide, Template, & Examples

What is a Literature Review? | Guide, Template, & Examples

Published on 22 February 2022 by Shona McCombes . Revised on 7 June 2022.

What is a literature review? A literature review is a survey of scholarly sources on a specific topic. It provides an overview of current knowledge, allowing you to identify relevant theories, methods, and gaps in the existing research.

There are five key steps to writing a literature review:

• Search for relevant literature
• Evaluate sources
• Identify themes, debates and gaps
• Outline the structure
• Write your literature review

A good literature review doesn’t just summarise sources – it analyses, synthesises, and critically evaluates to give a clear picture of the state of knowledge on the subject.

Instantly correct all language mistakes in your text

Be assured that you'll submit flawless writing. Upload your document to correct all your mistakes.

Table of contents

Why write a literature review, examples of literature reviews, step 1: search for relevant literature, step 2: evaluate and select sources, step 3: identify themes, debates and gaps, step 4: outline your literature review’s structure, step 5: write your literature review, frequently asked questions about literature reviews, introduction.

• Quick Run-through
• Step 1 & 2

When you write a dissertation or thesis, you will have to conduct a literature review to situate your research within existing knowledge. The literature review gives you a chance to:

• Demonstrate your familiarity with the topic and scholarly context
• Develop a theoretical framework and methodology for your research
• Position yourself in relation to other researchers and theorists
• Show how your dissertation addresses a gap or contributes to a debate

You might also have to write a literature review as a stand-alone assignment. In this case, the purpose is to evaluate the current state of research and demonstrate your knowledge of scholarly debates around a topic.

The content will look slightly different in each case, but the process of conducting a literature review follows the same steps. We’ve written a step-by-step guide that you can follow below.

Prevent plagiarism, run a free check.

Writing literature reviews can be quite challenging! A good starting point could be to look at some examples, depending on what kind of literature review you’d like to write.

• Example literature review #1: “Why Do People Migrate? A Review of the Theoretical Literature” ( Theoretical literature review about the development of economic migration theory from the 1950s to today.)
• Example literature review #2: “Literature review as a research methodology: An overview and guidelines” ( Methodological literature review about interdisciplinary knowledge acquisition and production.)
• Example literature review #3: “The Use of Technology in English Language Learning: A Literature Review” ( Thematic literature review about the effects of technology on language acquisition.)
• Example literature review #4: “Learners’ Listening Comprehension Difficulties in English Language Learning: A Literature Review” ( Chronological literature review about how the concept of listening skills has changed over time.)

You can also check out our templates with literature review examples and sample outlines at the links below.

Download Word doc Download Google doc

Before you begin searching for literature, you need a clearly defined topic .

If you are writing the literature review section of a dissertation or research paper, you will search for literature related to your research objectives and questions .

If you are writing a literature review as a stand-alone assignment, you will have to choose a focus and develop a central question to direct your search. Unlike a dissertation research question, this question has to be answerable without collecting original data. You should be able to answer it based only on a review of existing publications.

Make a list of keywords

Start by creating a list of keywords related to your research topic. Include each of the key concepts or variables you’re interested in, and list any synonyms and related terms. You can add to this list if you discover new keywords in the process of your literature search.

• Social media, Facebook, Instagram, Twitter, Snapchat, TikTok
• Body image, self-perception, self-esteem, mental health
• Generation Z, teenagers, adolescents, youth

Search for relevant sources

Use your keywords to begin searching for sources. Some databases to search for journals and articles include:

• Your university’s library catalogue
• Google Scholar
• Project Muse (humanities and social sciences)
• Medline (life sciences and biomedicine)
• EconLit (economics)
• Inspec (physics, engineering and computer science)

You can use boolean operators to help narrow down your search:

Read the abstract to find out whether an article is relevant to your question. When you find a useful book or article, you can check the bibliography to find other relevant sources.

To identify the most important publications on your topic, take note of recurring citations. If the same authors, books or articles keep appearing in your reading, make sure to seek them out.

You probably won’t be able to read absolutely everything that has been written on the topic – you’ll have to evaluate which sources are most relevant to your questions.

For each publication, ask yourself:

• What question or problem is the author addressing?
• What are the key concepts and how are they defined?
• What are the key theories, models and methods? Does the research use established frameworks or take an innovative approach?
• What are the results and conclusions of the study?
• How does the publication relate to other literature in the field? Does it confirm, add to, or challenge established knowledge?
• How does the publication contribute to your understanding of the topic? What are its key insights and arguments?
• What are the strengths and weaknesses of the research?

Make sure the sources you use are credible, and make sure you read any landmark studies and major theories in your field of research.

You can find out how many times an article has been cited on Google Scholar – a high citation count means the article has been influential in the field, and should certainly be included in your literature review.

The scope of your review will depend on your topic and discipline: in the sciences you usually only review recent literature, but in the humanities you might take a long historical perspective (for example, to trace how a concept has changed in meaning over time).

Remember that you can use our template to summarise and evaluate sources you’re thinking about using!

Take notes and cite your sources

As you read, you should also begin the writing process. Take notes that you can later incorporate into the text of your literature review.

It’s important to keep track of your sources with references to avoid plagiarism . It can be helpful to make an annotated bibliography, where you compile full reference information and write a paragraph of summary and analysis for each source. This helps you remember what you read and saves time later in the process.

You can use our free APA Reference Generator for quick, correct, consistent citations.

To begin organising your literature review’s argument and structure, you need to understand the connections and relationships between the sources you’ve read. Based on your reading and notes, you can look for:

• Trends and patterns (in theory, method or results): do certain approaches become more or less popular over time?
• Themes: what questions or concepts recur across the literature?
• Debates, conflicts and contradictions: where do sources disagree?
• Pivotal publications: are there any influential theories or studies that changed the direction of the field?
• Gaps: what is missing from the literature? Are there weaknesses that need to be addressed?

This step will help you work out the structure of your literature review and (if applicable) show how your own research will contribute to existing knowledge.

• Most research has focused on young women.
• There is an increasing interest in the visual aspects of social media.
• But there is still a lack of robust research on highly-visual platforms like Instagram and Snapchat – this is a gap that you could address in your own research.

There are various approaches to organising the body of a literature review. You should have a rough idea of your strategy before you start writing.

Depending on the length of your literature review, you can combine several of these strategies (for example, your overall structure might be thematic, but each theme is discussed chronologically).

Chronological

The simplest approach is to trace the development of the topic over time. However, if you choose this strategy, be careful to avoid simply listing and summarising sources in order.

Try to analyse patterns, turning points and key debates that have shaped the direction of the field. Give your interpretation of how and why certain developments occurred.

If you have found some recurring central themes, you can organise your literature review into subsections that address different aspects of the topic.

For example, if you are reviewing literature about inequalities in migrant health outcomes, key themes might include healthcare policy, language barriers, cultural attitudes, legal status, and economic access.

Methodological

If you draw your sources from different disciplines or fields that use a variety of research methods , you might want to compare the results and conclusions that emerge from different approaches. For example:

• Look at what results have emerged in qualitative versus quantitative research
• Discuss how the topic has been approached by empirical versus theoretical scholarship
• Divide the literature into sociological, historical, and cultural sources

Theoretical

A literature review is often the foundation for a theoretical framework . You can use it to discuss various theories, models, and definitions of key concepts.

You might argue for the relevance of a specific theoretical approach, or combine various theoretical concepts to create a framework for your research.

Like any other academic text, your literature review should have an introduction , a main body, and a conclusion . What you include in each depends on the objective of your literature review.

The introduction should clearly establish the focus and purpose of the literature review.

If you are writing the literature review as part of your dissertation or thesis, reiterate your central problem or research question and give a brief summary of the scholarly context. You can emphasise the timeliness of the topic (“many recent studies have focused on the problem of x”) or highlight a gap in the literature (“while there has been much research on x, few researchers have taken y into consideration”).

Depending on the length of your literature review, you might want to divide the body into subsections. You can use a subheading for each theme, time period, or methodological approach.

As you write, make sure to follow these tips:

• Summarise and synthesise: give an overview of the main points of each source and combine them into a coherent whole.
• Analyse and interpret: don’t just paraphrase other researchers – add your own interpretations, discussing the significance of findings in relation to the literature as a whole.
• Critically evaluate: mention the strengths and weaknesses of your sources.
• Write in well-structured paragraphs: use transitions and topic sentences to draw connections, comparisons and contrasts.

In the conclusion, you should summarise the key findings you have taken from the literature and emphasise their significance.

If the literature review is part of your dissertation or thesis, reiterate how your research addresses gaps and contributes new knowledge, or discuss how you have drawn on existing theories and methods to build a framework for your research. This can lead directly into your methodology section.

A literature review is a survey of scholarly sources (such as books, journal articles, and theses) related to a specific topic or research question .

It is often written as part of a dissertation , thesis, research paper , or proposal .

There are several reasons to conduct a literature review at the beginning of a research project:

• To familiarise yourself with the current state of knowledge on your topic
• To ensure that you’re not just repeating what others have already done
• To identify gaps in knowledge and unresolved problems that your research can address
• To develop your theoretical framework and methodology
• To provide an overview of the key findings and debates on the topic

Writing the literature review shows your reader how your work relates to existing research and what new insights it will contribute.

The literature review usually comes near the beginning of your  dissertation . After the introduction , it grounds your research in a scholarly field and leads directly to your theoretical framework or methodology .

Cite this Scribbr article

If you want to cite this source, you can copy and paste the citation or click the ‘Cite this Scribbr article’ button to automatically add the citation to our free Reference Generator.

McCombes, S. (2022, June 07). What is a Literature Review? | Guide, Template, & Examples. Scribbr. Retrieved 21 May 2024, from https://www.scribbr.co.uk/thesis-dissertation/literature-review/

Is this article helpful?

Shona McCombes

Other students also liked, how to write a dissertation proposal | a step-by-step guide, what is a theoretical framework | a step-by-step guide, what is a research methodology | steps & tips.

• University of Texas Libraries

Literature Reviews

• What is a literature review?
• Steps in the Literature Review Process
• Define your research question
• Determine inclusion and exclusion criteria
• Choose databases and search
• Review Results
• Synthesize Results
• Analyze Results
• Librarian Support

What is a Literature Review?

A literature or narrative review is a comprehensive review and analysis of the published literature on a specific topic or research question. The literature that is reviewed contains: books, articles, academic articles, conference proceedings, association papers, and dissertations. It contains the most pertinent studies and points to important past and current research and practices. It provides background and context, and shows how your research will contribute to the field. 

A literature review should: 

• Provide a comprehensive and updated review of the literature;
• Explain why this review has taken place;
• Articulate a position or hypothesis;
• Acknowledge and account for conflicting and corroborating points of view

From  S age Research Methods

Purpose of a Literature Review

A literature review can be written as an introduction to a study to:

• Demonstrate how a study fills a gap in research
• Compare a study with other research that's been done

Or it can be a separate work (a research article on its own) which:

• Organizes or describes a topic
• Describes variables within a particular issue/problem

Limitations of a Literature Review

Some of the limitations of a literature review are:

• It's a snapshot in time. Unlike other reviews, this one has beginning, a middle and an end. There may be future developments that could make your work less relevant.
• It may be too focused. Some niche studies may miss the bigger picture.
• It can be difficult to be comprehensive. There is no way to make sure all the literature on a topic was considered.
• It is easy to be biased if you stick to top tier journals. There may be other places where people are publishing exemplary research. Look to open access publications and conferences to reflect a more inclusive collection. Also, make sure to include opposing views (and not just supporting evidence).

Source: Grant, Maria J., and Andrew Booth. “A Typology of Reviews: An Analysis of 14 Review Types and Associated Methodologies.” Health Information & Libraries Journal, vol. 26, no. 2, June 2009, pp. 91–108. Wiley Online Library, doi:10.1111/j.1471-1842.2009.00848.x.

Meryl Brodsky : Communication and Information Studies

Hannah Chapman Tripp : Biology, Neuroscience

Carolyn Cunningham : Human Development & Family Sciences, Psychology, Sociology

Larayne Dallas : Engineering

Janelle Hedstrom : Special Education, Curriculum & Instruction, Ed Leadership & Policy ​

Susan Macicak : Linguistics

Imelda Vetter : Dell Medical School

For help in other subject areas, please see the guide to library specialists by subject .

Periodically, UT Libraries runs a workshop covering the basics and library support for literature reviews. While we try to offer these once per academic year, we find providing the recording to be helpful to community members who have missed the session. Following is the most recent recording of the workshop, Conducting a Literature Review. To view the recording, a UT login is required.

• October 26, 2022 recording
• Last Updated: Oct 26, 2022 2:49 PM
• URL: https://guides.lib.utexas.edu/literaturereviews

Research Process :: Step by Step

• Introduction
• Select Topic
• Identify Keywords
• Background Information
• Develop Research Questions
• Refine Topic
• Search Strategy
• Popular Databases
• Evaluate Sources
• Types of Periodicals
• Reading Scholarly Articles
• Primary & Secondary Sources
• Organize / Take Notes
• Writing & Grammar Resources
• Annotated Bibliography
• Literature Review
• Citation Styles
• Paraphrasing
• Privacy / Confidentiality
• Research Process
• Selecting Your Topic
• Identifying Keywords
• Gathering Background Info
• Evaluating Sources

Organize the literature review into sections that present themes or identify trends, including relevant theory. You are not trying to list all the material published, but to synthesize and evaluate it according to the guiding concept of your thesis or research question.  

What is a literature review?

A literature review is an account of what has been published on a topic by accredited scholars and researchers. Occasionally you will be asked to write one as a separate assignment, but more often it is part of the introduction to an essay, research report, or thesis. In writing the literature review, your purpose is to convey to your reader what knowledge and ideas have been established on a topic, and what their strengths and weaknesses are. As a piece of writing, the literature review must be defined by a guiding concept (e.g., your research objective, the problem or issue you are discussing, or your argumentative thesis). It is not just a descriptive list of the material available, or a set of summaries

A literature review must do these things:

• be organized around and related directly to the thesis or research question you are developing
• synthesize results into a summary of what is and is not known
• identify areas of controversy in the literature
• formulate questions that need further research

Ask yourself questions like these:

• What is the specific thesis, problem, or research question that my literature review helps to define?
• What type of literature review am I conducting? Am I looking at issues of theory? methodology? policy? quantitative research (e.g. on the effectiveness of a new procedure)? qualitative research (e.g., studies of loneliness among migrant workers)?
• What is the scope of my literature review? What types of publications am I using (e.g., journals, books, government documents, popular media)? What discipline am I working in (e.g., nursing psychology, sociology, medicine)?
• How good was my information seeking? Has my search been wide enough to ensure I've found all the relevant material? Has it been narrow enough to exclude irrelevant material? Is the number of sources I've used appropriate for the length of my paper?
• Have I critically analyzed the literature I use? Do I follow through a set of concepts and questions, comparing items to each other in the ways they deal with them? Instead of just listing and summarizing items, do I assess them, discussing strengths and weaknesses?
• Have I cited and discussed studies contrary to my perspective?
• Will the reader find my literature review relevant, appropriate, and useful?

Ask yourself questions like these about each book or article you include:

• Has the author formulated a problem/issue?
• Is it clearly defined? Is its significance (scope, severity, relevance) clearly established?
• Could the problem have been approached more effectively from another perspective?
• What is the author's research orientation (e.g., interpretive, critical science, combination)?
• What is the author's theoretical framework (e.g., psychological, developmental, feminist)?
• What is the relationship between the theoretical and research perspectives?
• Has the author evaluated the literature relevant to the problem/issue? Does the author include literature taking positions she or he does not agree with?
• In a research study, how good are the basic components of the study design (e.g., population, intervention, outcome)? How accurate and valid are the measurements? Is the analysis of the data accurate and relevant to the research question? Are the conclusions validly based upon the data and analysis?
• In material written for a popular readership, does the author use appeals to emotion, one-sided examples, or rhetorically-charged language and tone? Is there an objective basis to the reasoning, or is the author merely "proving" what he or she already believes?
• How does the author structure the argument? Can you "deconstruct" the flow of the argument to see whether or where it breaks down logically (e.g., in establishing cause-effect relationships)?
• In what ways does this book or article contribute to our understanding of the problem under study, and in what ways is it useful for practice? What are the strengths and limitations?
• How does this book or article relate to the specific thesis or question I am developing?

Text written by Dena Taylor, Health Sciences Writing Centre, University of Toronto

http://www.writing.utoronto.ca/advice/specific-types-of-writing/literature-review

• << Previous: Annotated Bibliography
• Next: Step 5: Cite Sources >>
• Last Updated: May 21, 2024 10:11 AM
• URL: https://libguides.uta.edu/researchprocess

University of Texas Arlington Libraries 702 Planetarium Place · Arlington, TX 76019 · 817-272-3000

• Internet Privacy
• Accessibility
• Problems with a guide? Contact Us.

• Affiliate Program

• UNITED STATES
• 台灣 (TAIWAN)
• TÜRKIYE (TURKEY)
• Academic Editing Services
• - Research Paper
• - Journal Manuscript
• - Dissertation
• - College & University Assignments
• Admissions Editing Services
• - Application Essay
• - Personal Statement
• - Recommendation Letter
• - Cover Letter
• - CV/Resume
• Business Editing Services
• - Business Documents
• - Report & Brochure
• - Website & Blog
• Writer Editing Services
• - Script & Screenplay
• Our Editors
• Client Reviews
• Editing & Proofreading Prices
• Wordvice Points
• Partner Discount
• Plagiarism Checker
• APA Citation Generator
• MLA Citation Generator
• Chicago Citation Generator
• Vancouver Citation Generator
• - APA Style
• - MLA Style
• - Chicago Style
• - Vancouver Style
• Writing & Editing Guide
• Academic Resources
• Admissions Resources

How to Make a Literature Review in Research (RRL Example)

What is an RRL in a research paper?

A relevant review of the literature (RRL) is an objective, concise, critical summary of published research literature relevant to a topic being researched in an article. In an RRL, you discuss knowledge and findings from existing literature relevant to your study topic. If there are conflicts or gaps in existing literature, you can also discuss these in your review, as well as how you will confront these missing elements or resolve these issues in your study.

To complete an RRL, you first need to collect relevant literature; this can include online and offline sources. Save all of your applicable resources as you will need to include them in your paper. When looking through these sources, take notes and identify concepts of each source to describe in the review of the literature.

A good RRL does NOT:

A literature review does not simply reference and list all of the material you have cited in your paper.

• Presenting material that is not directly relevant to your study will distract and frustrate the reader and make them lose sight of the purpose of your study.
• Starting a literature review with “A number of scholars have studied the relationship between X and Y” and simply listing who has studied the topic and what each scholar concluded is not going to strengthen your paper.

A good RRL DOES:

• Present a brief typology that orders articles and books into groups to help readers focus on unresolved debates, inconsistencies, tensions, and new questions about a research topic.
• Summarize the most relevant and important aspects of the scientific literature related to your area of research
• Synthesize what has been done in this area of research and by whom, highlight what previous research indicates about a topic, and identify potential gaps and areas of disagreement in the field
• Give the reader an understanding of the background of the field and show which studies are important—and highlight errors in previous studies

How long is a review of the literature for a research paper?

The length of a review of the literature depends on its purpose and target readership and can vary significantly in scope and depth. In a dissertation, thesis, or standalone review of literature, it is usually a full chapter of the text (at least 20 pages). Whereas, a standard research article or school assignment literature review section could only be a few paragraphs in the Introduction section .

Building Your Literature Review Bookshelf

One way to conceive of a literature review is to think about writing it as you would build a bookshelf. You don’t need to cut each piece by yourself from scratch. Rather, you can take the pieces that other researchers have cut out and put them together to build a framework on which to hang your own “books”—that is, your own study methods, results, and conclusions.

What Makes a Good Literature Review?

The contents of a literature review (RRL) are determined by many factors, including its precise purpose in the article, the degree of consensus with a given theory or tension between competing theories, the length of the article, the number of previous studies existing in the given field, etc. The following are some of the most important elements that a literature review provides.

Historical background for your research

Analyze what has been written about your field of research to highlight what is new and significant in your study—or how the analysis itself contributes to the understanding of this field, even in a small way. Providing a historical background also demonstrates to other researchers and journal editors your competency in discussing theoretical concepts. You should also make sure to understand how to paraphrase scientific literature to avoid plagiarism in your work.

The current context of your research

Discuss central (or peripheral) questions, issues, and debates in the field. Because a field is constantly being updated by new work, you can show where your research fits into this context and explain developments and trends in research.

A discussion of relevant theories and concepts

Theories and concepts should provide the foundation for your research. For example, if you are researching the relationship between ecological environments and human populations, provide models and theories that focus on specific aspects of this connection to contextualize your study. If your study asks a question concerning sustainability, mention a theory or model that underpins this concept. If it concerns invasive species, choose material that is focused in this direction.

Definitions of relevant terminology

In the natural sciences, the meaning of terms is relatively straightforward and consistent. But if you present a term that is obscure or context-specific, you should define the meaning of the term in the Introduction section (if you are introducing a study) or in the summary of the literature being reviewed.

Description of related relevant research

Include a description of related research that shows how your work expands or challenges earlier studies or fills in gaps in previous work. You can use your literature review as evidence of what works, what doesn’t, and what is missing in the field.

Supporting evidence for a practical problem or issue your research is addressing that demonstrates its importance: Referencing related research establishes your area of research as reputable and shows you are building upon previous work that other researchers have deemed significant.

Types of Literature Reviews

Literature reviews can differ in structure, length, amount, and breadth of content included. They can range from selective (a very narrow area of research or only a single work) to comprehensive (a larger amount or range of works). They can also be part of a larger work or stand on their own.

• A course assignment is an example of a selective, stand-alone work. It focuses on a small segment of the literature on a topic and makes up an entire work on its own.
• The literature review in a dissertation or thesis is both comprehensive and helps make up a larger work.
• A majority of journal articles start with a selective literature review to provide context for the research reported in the study; such a literature review is usually included in the Introduction section (but it can also follow the presentation of the results in the Discussion section ).
• Some literature reviews are both comprehensive and stand as a separate work—in this case, the entire article analyzes the literature on a given topic.

Literature Reviews Found in Academic Journals

The two types of literature reviews commonly found in journals are those introducing research articles (studies and surveys) and stand-alone literature analyses. They can differ in their scope, length, and specific purpose.

Literature reviews introducing research articles

The literature review found at the beginning of a journal article is used to introduce research related to the specific study and is found in the Introduction section, usually near the end. It is shorter than a stand-alone review because it must be limited to very specific studies and theories that are directly relevant to the current study. Its purpose is to set research precedence and provide support for the study’s theory, methods, results, and/or conclusions. Not all research articles contain an explicit review of the literature, but most do, whether it is a discrete section or indistinguishable from the rest of the Introduction.

How to structure a literature review for an article

When writing a literature review as part of an introduction to a study, simply follow the structure of the Introduction and move from the general to the specific—presenting the broadest background information about a topic first and then moving to specific studies that support your rationale , finally leading to your hypothesis statement. Such a literature review is often indistinguishable from the Introduction itself—the literature is INTRODUCING the background and defining the gaps your study aims to fill.

The stand-alone literature review

The literature review published as a stand-alone article presents and analyzes as many of the important publications in an area of study as possible to provide background information and context for a current area of research or a study. Stand-alone reviews are an excellent resource for researchers when they are first searching for the most relevant information on an area of study.

Such literature reviews are generally a bit broader in scope and can extend further back in time. This means that sometimes a scientific literature review can be highly theoretical, in addition to focusing on specific methods and outcomes of previous studies. In addition, all sections of such a “review article” refer to existing literature rather than describing the results of the authors’ own study.

In addition, this type of literature review is usually much longer than the literature review introducing a study. At the end of the review follows a conclusion that once again explicitly ties all of the cited works together to show how this analysis is itself a contribution to the literature. While not absolutely necessary, such articles often include the terms “Literature Review” or “Review of the Literature” in the title. Whether or not that is necessary or appropriate can also depend on the specific author instructions of the target journal. Have a look at this article for more input on how to compile a stand-alone review article that is insightful and helpful for other researchers in your field.

How to Write a Literature Review in 6 Steps

So how do authors turn a network of articles into a coherent review of relevant literature?

Writing a literature review is not usually a linear process—authors often go back and check the literature while reformulating their ideas or making adjustments to their study. Sometimes new findings are published before a study is completed and need to be incorporated into the current work. This also means you will not be writing the literature review at any one time, but constantly working on it before, during, and after your study is complete.

Here are some steps that will help you begin and follow through on your literature review.

Step 1: Choose a topic to write about—focus on and explore this topic.

Choose a topic that you are familiar with and highly interested in analyzing; a topic your intended readers and researchers will find interesting and useful; and a topic that is current, well-established in the field, and about which there has been sufficient research conducted for a review. This will help you find the “sweet spot” for what to focus on.

Step 2: Research and collect all the scholarly information on the topic that might be pertinent to your study.

This includes scholarly articles, books, conventions, conferences, dissertations, and theses—these and any other academic work related to your area of study is called “the literature.”

Step 3: Analyze the network of information that extends or responds to the major works in your area; select the material that is most useful.

Use thought maps and charts to identify intersections in the research and to outline important categories; select the material that will be most useful to your review.

Step 4: Describe and summarize each article—provide the essential information of the article that pertains to your study.

Determine 2-3 important concepts (depending on the length of your article) that are discussed in the literature; take notes about all of the important aspects of this study relevant to the topic being reviewed.

For example, in a given study, perhaps some of the main concepts are X, Y, and Z. Note these concepts and then write a brief summary about how the article incorporates them. In reviews that introduce a study, these can be relatively short. In stand-alone reviews, there may be significantly more texts and more concepts.

Step 5: Demonstrate how these concepts in the literature relate to what you discovered in your study or how the literature connects the concepts or topics being discussed.

In a literature review intro for an article, this information might include a summary of the results or methods of previous studies that correspond to and/or confirm those sections in your own study. For a stand-alone literature review, this may mean highlighting the concepts in each article and showing how they strengthen a hypothesis or show a pattern.

Discuss unaddressed issues in previous studies. These studies that are missing something you address are important to include in your literature review. In addition, those works whose theories and conclusions directly support your findings will be valuable to review here.

Step 6: Identify relationships in the literature and develop and connect your own ideas to them.

This is essentially the same as step 5 but focused on the connections between the literature and the current study or guiding concepts or arguments of the paper, not only on the connections between the works themselves.

Your hypothesis, argument, or guiding concept is the “golden thread” that will ultimately tie the works together and provide readers with specific insights they didn’t have before reading your literature review. Make sure you know where to put the research question , hypothesis, or statement of the problem in your research paper so that you guide your readers logically and naturally from your introduction of earlier work and evidence to the conclusions you want them to draw from the bigger picture.

Your literature review will not only cover publications on your topics but will include your own ideas and contributions. By following these steps you will be telling the specific story that sets the background and shows the significance of your research and you can turn a network of related works into a focused review of the literature.

Literature Review (RRL) Examples

Because creating sample literature reviews would take too long and not properly capture the nuances and detailed information needed for a good review, we have included some links to different types of literature reviews below. You can find links to more literature reviews in these categories by visiting the TUS Library’s website . Sample literature reviews as part of an article, dissertation, or thesis:

• Critical Thinking and Transferability: A Review of the Literature (Gwendolyn Reece)
• Building Customer Loyalty: A Customer Experience Based Approach in a Tourism Context (Martina Donnelly)

Sample stand-alone literature reviews

• Literature Review on Attitudes towards Disability (National Disability Authority)
• The Effects of Communication Styles on Marital Satisfaction (Hannah Yager)

Additional Literature Review Format Guidelines

In addition to the content guidelines above, authors also need to check which style guidelines to use ( APA , Chicago, MLA, etc.) and what specific rules the target journal might have for how to structure such articles or how many studies to include—such information can usually be found on the journals’ “Guide for Authors” pages. Additionally, use one of the four Wordvice citation generators below, choosing the citation style needed for your paper:

Wordvice Writing and Academic Editing Resources

Finally, after you have finished drafting your literature review, be sure to receive professional proofreading services , including paper editing for your academic work. A competent proofreader who understands academic writing conventions and the specific style guides used by academic journals will ensure that your paper is ready for publication in your target journal.

See our academic resources for further advice on references in your paper , how to write an abstract , how to write a research paper title, how to impress the editor of your target journal with a perfect cover letter , and dozens of other research writing and publication topics.

Learn how to write a review of literature

What is a review of literature.

The format of a review of literature may vary from discipline to discipline and from assignment to assignment.

A review may be a self-contained unit — an end in itself — or a preface to and rationale for engaging in primary research. A review is a required part of grant and research proposals and often a chapter in theses and dissertations.

Generally, the purpose of a review is to analyze critically a segment of a published body of knowledge through summary, classification, and comparison of prior research studies, reviews of literature, and theoretical articles.

Writing the introduction

In the introduction, you should:

Define or identify the general topic, issue, or area of concern, thus providing an appropriate context for reviewing the literature.

Point out overall trends in what has been published about the topic; or conflicts in theory, methodology, evidence, and conclusions; or gaps in research and scholarship; or a single problem or new perspective of immediate interest.

Establish the writer’s reason (point of view) for reviewing the literature; explain the criteria to be used in analyzing and comparing literature and the organization of the review (sequence); and, when necessary, state why certain literature is or is not included (scope).

Writing the body

In the body, you should:

Group research studies and other types of literature (reviews, theoretical articles, case studies, etc.) according to common denominators such as qualitative versus quantitative approaches, conclusions of authors, specific purpose or objective, chronology, etc.

Summarize individual studies or articles with as much or as little detail as each merits according to its comparative importance in the literature, remembering that space (length) denotes significance.

Provide the reader with strong “umbrella” sentences at beginnings of paragraphs, “signposts” throughout, and brief “so what” summary sentences at intermediate points in the review to aid in understanding comparisons and analyses.

Writing the conclusion

In the conclusion, you should:

Summarize major contributions of significant studies and articles to the body of knowledge under review, maintaining the focus established in the introduction.

Evaluate the current “state of the art” for the body of knowledge reviewed, pointing out major methodological flaws or gaps in research, inconsistencies in theory and findings, and areas or issues pertinent to future study.

Conclude by providing some insight into the relationship between the central topic of the literature review and a larger area of study such as a discipline, a scientific endeavor, or a profession.

For further information see our handouts on Writing a Critical Review of a Nonfiction Book or Article or Reading a Book to Review It .

To learn more about literature reviews, take a look at our workshop on Writing Literature Reviews of Published Research.

Sample Literature Reviews

An important strategy for learning how to compose literature reviews in your field or within a specific genre is to locate and analyze representative examples. The following collection of annotated sample literature reviews written and co-written by colleagues associated with UW-Madison showcases how these reviews can do different kind of work for different purposes. Use these successful examples as a starting point for understanding how other writers have approached the challenging and important task of situating their idea in the context of established research.

• Sample 1 (PDF) A brief literature review within a political scientists’  National Science Foundation Graduate Research Fellowship  grant
• Sample 2 (PDF) A several-page literature review at the beginning of a published, academic article about philosophy
• Sample 3 (PDF) A brief literature review at the beginning of a published, academic article about photochemistry

Academic and Professional Writing

This is an accordion element with a series of buttons that open and close related content panels.

Analysis Papers

Reading Poetry

A Short Guide to Close Reading for Literary Analysis

Using Literary Quotations

Play Reviews

Writing a Rhetorical Précis to Analyze Nonfiction Texts

Incorporating Interview Data

Grant Proposals

Planning and Writing a Grant Proposal: The Basics

Additional Resources for Grants and Proposal Writing

Job Materials and Application Essays

Writing Personal Statements for Ph.D. Programs

• Before you begin: useful tips for writing your essay
• Guided brainstorming exercises
• Get more help with your essay
• Frequently Asked Questions

Resume Writing Tips

CV Writing Tips

Cover Letters

Business Letters

Proposals and Dissertations

Resources for Proposal Writers

Resources for Dissertators

Research Papers

Planning and Writing Research Papers

Quoting and Paraphrasing

Writing Annotated Bibliographies

Creating Poster Presentations

Writing an Abstract for Your Research Paper

Thank-You Notes

Advice for Students Writing Thank-You Notes to Donors

Reading for a Review

Critical Reviews

Writing a Review of Literature

Scientific Reports

Scientific Report Format

Sample Lab Assignment

Writing for the Web

Writing an Effective Blog Post

Writing for Social Media: A Guide for Academics

Review of Related Literature: Format, Example, & How to Make RRL

A review of related literature is a separate paper or a part of an article that collects and synthesizes discussion on a topic. Its purpose is to show the current state of research on the issue and highlight gaps in existing knowledge. A literature review can be included in a research paper or scholarly article, typically following the introduction and before the research methods section.

This article will clarify the definition, significance, and structure of a review of related literature. You’ll also learn how to organize your literature review and discover ideas for an RRL in different subjects.

🔤 What Is RRL?

• ❗ Significance of Literature Review
• 🔎 How to Search for Literature
• 🧩 Literature Review Structure
• 📋 Format of RRL — APA, MLA, & Others
• ✍️ How to Write an RRL
• 📚 Examples of RRL

🔗 References

A review of related literature (RRL) is a part of the research report that examines significant studies, theories, and concepts published in scholarly sources on a particular topic. An RRL includes 3 main components:

• A short overview and critique of the previous research.
• Similarities and differences between past studies and the current one.
• An explanation of the theoretical frameworks underpinning the research.

❗ Significance of Review of Related Literature

Although the goal of a review of related literature differs depending on the discipline and its intended use, its significance cannot be overstated. Here are some examples of how a review might be beneficial:

• It helps determine knowledge gaps .
• It saves from duplicating research that has already been conducted.
• It provides an overview of various research areas within the discipline.
• It demonstrates the researcher’s familiarity with the topic.

🔎 How to Perform a Literature Search

Including a description of your search strategy in the literature review section can significantly increase your grade. You can search sources with the following steps:

🧩 Literature Review Structure Example

The majority of literature reviews follow a standard introduction-body-conclusion structure. Let’s look at the RRL structure in detail.

Introduction of Review of Related Literature: Sample

An introduction should clarify the study topic and the depth of the information to be delivered. It should also explain the types of sources used. If your lit. review is part of a larger research proposal or project, you can combine its introductory paragraph with the introduction of your paper.

Here is a sample introduction to an RRL about cyberbullying:

Bullying has troubled people since the beginning of time. However, with modern technological advancements, especially social media, bullying has evolved into cyberbullying. As a result, nowadays, teenagers and adults cannot flee their bullies, which makes them feel lonely and helpless. This literature review will examine recent studies on cyberbullying.

Sample Review of Related Literature Thesis

A thesis statement should include the central idea of your literature review and the primary supporting elements you discovered in the literature. Thesis statements are typically put at the end of the introductory paragraph.

Look at a sample thesis of a review of related literature:

This literature review shows that scholars have recently covered the issues of bullies’ motivation, the impact of bullying on victims and aggressors, common cyberbullying techniques, and victims’ coping strategies. However, there is still no agreement on the best practices to address cyberbullying.

Literature Review Body Paragraph Example

The main body of a literature review should provide an overview of the existing research on the issue. Body paragraphs should not just summarize each source but analyze them. You can organize your paragraphs with these 3 elements:

• Claim . Start with a topic sentence linked to your literature review purpose.
• Evidence . Cite relevant information from your chosen sources.
• Discussion . Explain how the cited data supports your claim.

Here’s a literature review body paragraph example:

Scholars have examined the link between the aggressor and the victim. Beran et al. (2007) state that students bullied online often become cyberbullies themselves. Faucher et al. (2014) confirm this with their findings: they discovered that male and female students began engaging in cyberbullying after being subject to bullying. Hence, one can conclude that being a victim of bullying increases one’s likelihood of becoming a cyberbully.

Review of Related Literature: Conclusion

A conclusion presents a general consensus on the topic. Depending on your literature review purpose, it might include the following:

• Introduction to further research . If you write a literature review as part of a larger research project, you can present your research question in your conclusion .
• Overview of theories . You can summarize critical theories and concepts to help your reader understand the topic better.
• Discussion of the gap . If you identified a research gap in the reviewed literature, your conclusion could explain why that gap is significant.

Check out a conclusion example that discusses a research gap:

There is extensive research into bullies’ motivation, the consequences of bullying for victims and aggressors, strategies for bullying, and coping with it. Yet, scholars still have not reached a consensus on what to consider the best practices to combat cyberbullying. This question is of great importance because of the significant adverse effects of cyberbullying on victims and bullies.

📋 Format of RRL — APA, MLA, & Others

In this section, we will discuss how to format an RRL according to the most common citation styles: APA, Chicago, MLA, and Harvard.

Writing a literature review using the APA7 style requires the following text formatting:

• When using APA in-text citations , include the author’s last name and the year of publication in parentheses.
• For direct quotations , you must also add the page number. If you use sources without page numbers, such as websites or e-books, include a paragraph number instead.
• When referring to the author’s name in a sentence , you do not need to repeat it at the end of the sentence. Instead, include the year of publication inside the parentheses after their name.
• The reference list should be included at the end of your literature review. It is always alphabetized by the last name of the author (from A to Z), and the lines are indented one-half inch from the left margin of your paper. Do not forget to invert authors’ names (the last name should come first) and include the full titles of journals instead of their abbreviations. If you use an online source, add its URL.

The RRL format in the Chicago style is as follows:

• Author-date . You place your citations in brackets within the text, indicating the name of the author and the year of publication.
• Notes and bibliography . You place your citations in numbered footnotes or endnotes to connect the citation back to the source in the bibliography.
• The reference list, or bibliography , in Chicago style, is at the end of a literature review. The sources are arranged alphabetically and single-spaced. Each bibliography entry begins with the author’s name and the source’s title, followed by publication information, such as the city of publication, the publisher, and the year of publication.

Writing a literature review using the MLA style requires the following text formatting:

• In the MLA format, you can cite a source in the text by indicating the author’s last name and the page number in parentheses at the end of the citation. If the cited information takes several pages, you need to include all the page numbers.
• The reference list in MLA style is titled “ Works Cited .” In this section, all sources used in the paper should be listed in alphabetical order. Each entry should contain the author, title of the source, title of the journal or a larger volume, other contributors, version, number, publisher, and publication date.

The Harvard style requires you to use the following text formatting for your RRL:

• In-text citations in the Harvard style include the author’s last name and the year of publication. If you are using a direct quote in your literature review, you need to add the page number as well.
• Arrange your list of references alphabetically. Each entry should contain the author’s last name, their initials, the year of publication, the title of the source, and other publication information, like the journal title and issue number or the publisher.

✍️ How to Write Review of Related Literature – Sample

Literature reviews can be organized in many ways depending on what you want to achieve with them. In this section, we will look at 3 examples of how you can write your RRL.

Thematic Literature Review

A thematic literature review is arranged around central themes or issues discussed in the sources. If you have identified some recurring themes in the literature, you can divide your RRL into sections that address various aspects of the topic. For example, if you examine studies on e-learning, you can distinguish such themes as the cost-effectiveness of online learning, the technologies used, and its effectiveness compared to traditional education.

Chronological Literature Review

A chronological literature review is a way to track the development of the topic over time. If you use this method, avoid merely listing and summarizing sources in chronological order. Instead, try to analyze the trends, turning moments, and critical debates that have shaped the field’s path. Also, you can give your interpretation of how and why specific advances occurred.

Methodological Literature Review

A methodological literature review differs from the preceding ones in that it usually doesn’t focus on the sources’ content. Instead, it is concerned with the research methods . So, if your references come from several disciplines or fields employing various research techniques, you can compare the findings and conclusions of different methodologies, for instance:

• empirical vs. theoretical studies;
• qualitative vs. quantitative research.

📚 Examples of Review of Related Literature and Studies

We have prepared a short example of RRL on climate change for you to see how everything works in practice!

Climate change is one of the most important issues nowadays. Based on a variety of facts, it is now clearer than ever that humans are altering the Earth's climate. The atmosphere and oceans have warmed, causing sea level rise, a significant loss of Arctic ice, and other climate-related changes. This literature review provides a thorough summary of research on climate change, focusing on climate change fingerprints and evidence of human influence on the Earth's climate system.

Physical Mechanisms and Evidence of Human Influence

Scientists are convinced that climate change is directly influenced by the emission of greenhouse gases. They have carefully analyzed various climate data and evidence, concluding that the majority of the observed global warming over the past 50 years cannot be explained by natural factors alone. Instead, there is compelling evidence pointing to a significant contribution of human activities, primarily the emission of greenhouse gases (Walker, 2014). For example, based on simple physics calculations, doubled carbon dioxide concentration in the atmosphere can lead to a global temperature increase of approximately 1 degree Celsius. (Elderfield, 2022). In order to determine the human influence on climate, scientists still have to analyze a lot of natural changes that affect temperature, precipitation, and other components of climate on timeframes ranging from days to decades and beyond.

Fingerprinting Climate Change

Fingerprinting climate change is a useful tool to identify the causes of global warming because different factors leave unique marks on climate records. This is evident when scientists look beyond overall temperature changes and examine how warming is distributed geographically and over time (Watson, 2022). By investigating these climate patterns, scientists can obtain a more complex understanding of the connections between natural climate variability and climate variability caused by human activity.

Modeling Climate Change and Feedback

To accurately predict the consequences of feedback mechanisms, the rate of warming, and regional climate change, scientists can employ sophisticated mathematical models of the atmosphere, ocean, land, and ice (the cryosphere). These models are grounded in well-established physical laws and incorporate the latest scientific understanding of climate-related processes (Shuckburgh, 2013). Although different climate models produce slightly varying projections for future warming, they all will agree that feedback mechanisms play a significant role in amplifying the initial warming caused by greenhouse gas emissions. (Meehl, 2019).

In conclusion, the literature on global warming indicates that there are well-understood physical processes that link variations in greenhouse gas concentrations to climate change. In addition, it covers the scientific proof that the rates of these gases in the atmosphere have increased and continue to rise fast. According to the sources, the majority of this recent change is almost definitely caused by greenhouse gas emissions produced by human activities. Citizens and governments can alter their energy production methods and consumption patterns to reduce greenhouse gas emissions and, thus, the magnitude of climate change. By acting now, society can prevent the worst consequences of climate change and build a more resilient and sustainable future for generations to come.

Have you ever struggled with finding the topic for an RRL in different subjects? Read the following paragraphs to get some ideas!

Nursing Literature Review Example

Many topics in the nursing field require research. For example, you can write a review of literature related to dengue fever . Give a general overview of dengue virus infections, including its clinical symptoms, diagnosis, prevention, and therapy.

Another good idea is to review related literature and studies about teenage pregnancy . This review can describe the effectiveness of specific programs for adolescent mothers and their children and summarize recommendations for preventing early pregnancy.

📝 Check out some more valuable examples below:

• Hospital Readmissions: Literature Review .
• Literature Review: Lower Sepsis Mortality Rates .
• Breast Cancer: Literature Review .
• Sexually Transmitted Diseases: Literature Review .
• PICO for Pressure Ulcers: Literature Review .
• COVID-19 Spread Prevention: Literature Review .
• Chronic Obstructive Pulmonary Disease: Literature Review .
• Hypertension Treatment Adherence: Literature Review .
• Neonatal Sepsis Prevention: Literature Review .
• Healthcare-Associated Infections: Literature Review .
• Understaffing in Nursing: Literature Review .

Psychology Literature Review Example

If you look for an RRL topic in psychology , you can write a review of related literature about stress . Summarize scientific evidence about stress stages, side effects, types, or reduction strategies. Or you can write a review of related literature about computer game addiction . In this case, you may concentrate on the neural mechanisms underlying the internet gaming disorder, compare it to other addictions, or evaluate treatment strategies.

A review of related literature about cyberbullying is another interesting option. You can highlight the impact of cyberbullying on undergraduate students’ academic, social, and emotional development.

📝 Look at the examples that we have prepared for you to come up with some more ideas:

• Mindfulness in Counseling: A Literature Review .
• Team-Building Across Cultures: Literature Review .
• Anxiety and Decision Making: Literature Review .
• Literature Review on Depression .
• Literature Review on Narcissism .
• Effects of Depression Among Adolescents .
• Causes and Effects of Anxiety in Children .

Literature Review — Sociology Example

Sociological research poses critical questions about social structures and phenomena. For example, you can write a review of related literature about child labor , exploring cultural beliefs and social norms that normalize the exploitation of children. Or you can create a review of related literature about social media . It can investigate the impact of social media on relationships between adolescents or the role of social networks on immigrants’ acculturation .

📝 You can find some more ideas below!

• Single Mothers’ Experiences of Relationships with Their Adolescent Sons .
• Teachers and Students’ Gender-Based Interactions .
• Gender Identity: Biological Perspective and Social Cognitive Theory .
• Gender: Culturally-Prescribed Role or Biological Sex .
• The Influence of Opioid Misuse on Academic Achievement of Veteran Students .
• The Importance of Ethics in Research .
• The Role of Family and Social Network Support in Mental Health .

Education Literature Review Example

For your education studies , you can write a review of related literature about academic performance to determine factors that affect student achievement and highlight research gaps. One more idea is to create a review of related literature on study habits , considering their role in the student’s life and academic outcomes.

You can also evaluate a computerized grading system in a review of related literature to single out its advantages and barriers to implementation. Or you can complete a review of related literature on instructional materials to identify their most common types and effects on student achievement.

📝 Find some inspiration in the examples below:

• Literature Review on Online Learning Challenges From COVID-19 .
• Education, Leadership, and Management: Literature Review .
• Literature Review: Standardized Testing Bias .
• Bullying of Disabled Children in School .
• Interventions and Letter & Sound Recognition: A Literature Review .
• Social-Emotional Skills Program for Preschoolers .
• Effectiveness of Educational Leadership Management Skills .

Business Research Literature Review

If you’re a business student, you can focus on customer satisfaction in your review of related literature. Discuss specific customer satisfaction features and how it is affected by service quality and prices. You can also create a theoretical literature review about consumer buying behavior to evaluate theories that have significantly contributed to understanding how consumers make purchasing decisions.

📝 Look at the examples to get more exciting ideas:

• Leadership and Communication: Literature Review .
• Human Resource Development: Literature Review .
• Project Management. Literature Review .
• Strategic HRM: A Literature Review .
• Customer Relationship Management: Literature Review .
• Literature Review on International Financial Reporting Standards .
• Cultures of Management: Literature Review .

To conclude, a review of related literature is a significant genre of scholarly works that can be applied in various disciplines and for multiple goals. The sources examined in an RRL provide theoretical frameworks for future studies and help create original research questions and hypotheses.

When you finish your outstanding literature review, don’t forget to check whether it sounds logical and coherent. Our text-to-speech tool can help you with that!

• Literature Reviews | University of North Carolina at Chapel Hill
• Writing a Literature Review | Purdue Online Writing Lab
• Learn How to Write a Review of Literature | University of Wisconsin-Madison
• The Literature Review: A Few Tips on Conducting It | University of Toronto
• Writing a Literature Review | UC San Diego
• Conduct a Literature Review | The University of Arizona
• Methods for Literature Reviews | National Library of Medicine
• Literature Reviews: 5. Write the Review | Georgia State University

How to Write an Animal Testing Essay: Tips for Argumentative & Persuasive Papers

Descriptive essay topics: examples, outline, & more.

Research Methods

• Getting Started
• Literature Review Research
• Research Design
• Research Design By Discipline
• SAGE Research Methods
• Teaching with SAGE Research Methods

Literature Review

• What is a Literature Review?
• What is NOT a Literature Review?
• Purposes of a Literature Review
• Types of Literature Reviews
• Literature Reviews vs. Systematic Reviews
• Systematic vs. Meta-Analysis

Literature Review  is a comprehensive survey of the works published in a particular field of study or line of research, usually over a specific period of time, in the form of an in-depth, critical bibliographic essay or annotated list in which attention is drawn to the most significant works.

Also, we can define a literature review as the collected body of scholarly works related to a topic:

• Summarizes and analyzes previous research relevant to a topic
• Includes scholarly books and articles published in academic journals
• Can be an specific scholarly paper or a section in a research paper

The objective of a Literature Review is to find previous published scholarly works relevant to an specific topic

• Help gather ideas or information
• Keep up to date in current trends and findings
• Help develop new questions

A literature review is important because it:

• Explains the background of research on a topic.
• Demonstrates why a topic is significant to a subject area.
• Helps focus your own research questions or problems
• Discovers relationships between research studies/ideas.
• Suggests unexplored ideas or populations
• Identifies major themes, concepts, and researchers on a topic.
• Tests assumptions; may help counter preconceived ideas and remove unconscious bias.
• Identifies critical gaps, points of disagreement, or potentially flawed methodology or theoretical approaches.
• Indicates potential directions for future research.

All content in this section is from Literature Review Research from Old Dominion University 

Keep in mind the following, a literature review is NOT:

Not an essay 

Not an annotated bibliography  in which you summarize each article that you have reviewed.  A literature review goes beyond basic summarizing to focus on the critical analysis of the reviewed works and their relationship to your research question.

Not a research paper   where you select resources to support one side of an issue versus another.  A lit review should explain and consider all sides of an argument in order to avoid bias, and areas of agreement and disagreement should be highlighted.

A literature review serves several purposes. For example, it

• provides thorough knowledge of previous studies; introduces seminal works.
• helps focus one’s own research topic.
• identifies a conceptual framework for one’s own research questions or problems; indicates potential directions for future research.
• suggests previously unused or underused methodologies, designs, quantitative and qualitative strategies.
• identifies gaps in previous studies; identifies flawed methodologies and/or theoretical approaches; avoids replication of mistakes.
• helps the researcher avoid repetition of earlier research.
• suggests unexplored populations.
• determines whether past studies agree or disagree; identifies controversy in the literature.
• tests assumptions; may help counter preconceived ideas and remove unconscious bias.

As Kennedy (2007) notes*, it is important to think of knowledge in a given field as consisting of three layers. First, there are the primary studies that researchers conduct and publish. Second are the reviews of those studies that summarize and offer new interpretations built from and often extending beyond the original studies. Third, there are the perceptions, conclusions, opinion, and interpretations that are shared informally that become part of the lore of field. In composing a literature review, it is important to note that it is often this third layer of knowledge that is cited as "true" even though it often has only a loose relationship to the primary studies and secondary literature reviews.

Given this, while literature reviews are designed to provide an overview and synthesis of pertinent sources you have explored, there are several approaches to how they can be done, depending upon the type of analysis underpinning your study. Listed below are definitions of types of literature reviews:

Argumentative Review      This form examines literature selectively in order to support or refute an argument, deeply imbedded assumption, or philosophical problem already established in the literature. The purpose is to develop a body of literature that establishes a contrarian viewpoint. Given the value-laden nature of some social science research [e.g., educational reform; immigration control], argumentative approaches to analyzing the literature can be a legitimate and important form of discourse. However, note that they can also introduce problems of bias when they are used to to make summary claims of the sort found in systematic reviews.

Integrative Review      Considered a form of research that reviews, critiques, and synthesizes representative literature on a topic in an integrated way such that new frameworks and perspectives on the topic are generated. The body of literature includes all studies that address related or identical hypotheses. A well-done integrative review meets the same standards as primary research in regard to clarity, rigor, and replication.

Historical Review      Few things rest in isolation from historical precedent. Historical reviews are focused on examining research throughout a period of time, often starting with the first time an issue, concept, theory, phenomena emerged in the literature, then tracing its evolution within the scholarship of a discipline. The purpose is to place research in a historical context to show familiarity with state-of-the-art developments and to identify the likely directions for future research.

Methodological Review      A review does not always focus on what someone said [content], but how they said it [method of analysis]. This approach provides a framework of understanding at different levels (i.e. those of theory, substantive fields, research approaches and data collection and analysis techniques), enables researchers to draw on a wide variety of knowledge ranging from the conceptual level to practical documents for use in fieldwork in the areas of ontological and epistemological consideration, quantitative and qualitative integration, sampling, interviewing, data collection and data analysis, and helps highlight many ethical issues which we should be aware of and consider as we go through our study.

Systematic Review      This form consists of an overview of existing evidence pertinent to a clearly formulated research question, which uses pre-specified and standardized methods to identify and critically appraise relevant research, and to collect, report, and analyse data from the studies that are included in the review. Typically it focuses on a very specific empirical question, often posed in a cause-and-effect form, such as "To what extent does A contribute to B?"

Theoretical Review      The purpose of this form is to concretely examine the corpus of theory that has accumulated in regard to an issue, concept, theory, phenomena. The theoretical literature review help establish what theories already exist, the relationships between them, to what degree the existing theories have been investigated, and to develop new hypotheses to be tested. Often this form is used to help establish a lack of appropriate theories or reveal that current theories are inadequate for explaining new or emerging research problems. The unit of analysis can focus on a theoretical concept or a whole theory or framework.

* Kennedy, Mary M. "Defining a Literature."  Educational Researcher  36 (April 2007): 139-147.

All content in this section is from The Literature Review created by Dr. Robert Larabee USC

Robinson, P. and Lowe, J. (2015),  Literature reviews vs systematic reviews.  Australian and New Zealand Journal of Public Health, 39: 103-103. doi: 10.1111/1753-6405.12393

What's in the name? The difference between a Systematic Review and a Literature Review, and why it matters . By Lynn Kysh from University of Southern California

Systematic review or meta-analysis?

A  systematic review  answers a defined research question by collecting and summarizing all empirical evidence that fits pre-specified eligibility criteria.

A  meta-analysis  is the use of statistical methods to summarize the results of these studies.

Systematic reviews, just like other research articles, can be of varying quality. They are a significant piece of work (the Centre for Reviews and Dissemination at York estimates that a team will take 9-24 months), and to be useful to other researchers and practitioners they should have:

• clearly stated objectives with pre-defined eligibility criteria for studies
• explicit, reproducible methodology
• a systematic search that attempts to identify all studies
• assessment of the validity of the findings of the included studies (e.g. risk of bias)
• systematic presentation, and synthesis, of the characteristics and findings of the included studies

Not all systematic reviews contain meta-analysis. 

Meta-analysis is the use of statistical methods to summarize the results of independent studies. By combining information from all relevant studies, meta-analysis can provide more precise estimates of the effects of health care than those derived from the individual studies included within a review.  More information on meta-analyses can be found in  Cochrane Handbook, Chapter 9 .

A meta-analysis goes beyond critique and integration and conducts secondary statistical analysis on the outcomes of similar studies.  It is a systematic review that uses quantitative methods to synthesize and summarize the results.

An advantage of a meta-analysis is the ability to be completely objective in evaluating research findings.  Not all topics, however, have sufficient research evidence to allow a meta-analysis to be conducted.  In that case, an integrative review is an appropriate strategy. 

Some of the content in this section is from Systematic reviews and meta-analyses: step by step guide created by Kate McAllister.

• << Previous: Getting Started
• Next: Research Design >>
• Last Updated: Aug 21, 2023 4:07 PM
• URL: https://guides.lib.udel.edu/researchmethods

Harvey Cushing/John Hay Whitney Medical Library

• Collections
• Research Help

YSN Doctoral Programs: Steps in Conducting a Literature Review

• Biomedical Databases
• Global (Public Health) Databases
• Soc. Sci., History, and Law Databases
• Grey Literature
• Trials Registers
• Data and Statistics
• Public Policy
• Google Tips
• Recommended Books
• Steps in Conducting a Literature Review

What is a literature review?

A literature review is an integrated analysis -- not just a summary-- of scholarly writings and other relevant evidence related directly to your research question.  That is, it represents a synthesis of the evidence that provides background information on your topic and shows a association between the evidence and your research question.

A literature review may be a stand alone work or the introduction to a larger research paper, depending on the assignment.  Rely heavily on the guidelines your instructor has given you.

Why is it important?

A literature review is important because it:

• Explains the background of research on a topic.
• Demonstrates why a topic is significant to a subject area.
• Discovers relationships between research studies/ideas.
• Identifies major themes, concepts, and researchers on a topic.
• Identifies critical gaps and points of disagreement.
• Discusses further research questions that logically come out of the previous studies.

APA7 Style resources

APA Style Blog - for those harder to find answers

1. Choose a topic. Define your research question.

Your literature review should be guided by your central research question.  The literature represents background and research developments related to a specific research question, interpreted and analyzed by you in a synthesized way.

• Make sure your research question is not too broad or too narrow.  Is it manageable?
• Begin writing down terms that are related to your question. These will be useful for searches later.
• If you have the opportunity, discuss your topic with your professor and your class mates.

2. Decide on the scope of your review

How many studies do you need to look at? How comprehensive should it be? How many years should it cover? 

• This may depend on your assignment.  How many sources does the assignment require?

3. Select the databases you will use to conduct your searches.

Make a list of the databases you will search. 

Where to find databases:

• use the tabs on this guide
• Find other databases in the Nursing Information Resources web page
• More on the Medical Library web page
• ... and more on the Yale University Library web page

4. Conduct your searches to find the evidence. Keep track of your searches.

• Use the key words in your question, as well as synonyms for those words, as terms in your search. Use the database tutorials for help.
• Save the searches in the databases. This saves time when you want to redo, or modify, the searches. It is also helpful to use as a guide is the searches are not finding any useful results.
• Review the abstracts of research studies carefully. This will save you time.
• Use the bibliographies and references of research studies you find to locate others.
• Check with your professor, or a subject expert in the field, if you are missing any key works in the field.
• Ask your librarian for help at any time.
• Use a citation manager, such as EndNote as the repository for your citations. See the EndNote tutorials for help.

Review the literature

Some questions to help you analyze the research:

• What was the research question of the study you are reviewing? What were the authors trying to discover?
• Was the research funded by a source that could influence the findings?
• What were the research methodologies? Analyze its literature review, the samples and variables used, the results, and the conclusions.
• Does the research seem to be complete? Could it have been conducted more soundly? What further questions does it raise?
• If there are conflicting studies, why do you think that is?
• How are the authors viewed in the field? Has this study been cited? If so, how has it been analyzed?

Tips: 

• Review the abstracts carefully.  
• Keep careful notes so that you may track your thought processes during the research process.
• Create a matrix of the studies for easy analysis, and synthesis, across all of the studies.
• << Previous: Recommended Books
• Last Updated: Jan 4, 2024 10:52 AM
• URL: https://guides.library.yale.edu/YSNDoctoral

• Subject List
• Take a Tour
• For Authors
• Subscriber Services
• Publications
• African American Studies
• African Studies
• American Literature
• Anthropology
• Architecture Planning and Preservation
• Art History
• Atlantic History
• Biblical Studies
• British and Irish Literature
• Childhood Studies
• Chinese Studies
• Cinema and Media Studies
• Communication
• Criminology
• Environmental Science
• Evolutionary Biology
• International Law
• International Relations
• Islamic Studies
• Jewish Studies
• Latin American Studies
• Latino Studies
• Linguistics
• Literary and Critical Theory
• Medieval Studies
• Military History
• Political Science
• Public Health
• Renaissance and Reformation
• Social Work
• Urban Studies
• Victorian Literature
• Browse All Subjects

How to Subscribe

• Free Trials

In This Article Expand or collapse the "in this article" section Literature Reviews

Introduction, what is a literature review.

• Literature Reviews for Thesis or Dissertation
• Stand-alone and Systemic Reviews
• Purposes of a Literature Review
• Texts on Conducting a Literature Review
• Identifying the Research Topic
• The Persuasive Argument
• Searching the Literature
• Creating a Synthesis
• Critiquing the Literature
• Building the Case for the Literature Review Document
• Presenting the Literature Review

Related Articles Expand or collapse the "related articles" section about

About related articles close popup.

Lorem Ipsum Sit Dolor Amet

Vestibulum ante ipsum primis in faucibus orci luctus et ultrices posuere cubilia Curae; Aliquam ligula odio, euismod ut aliquam et, vestibulum nec risus. Nulla viverra, arcu et iaculis consequat, justo diam ornare tellus, semper ultrices tellus nunc eu tellus.

• Higher Education Research
• Meta-Analysis and Research Synthesis in Education
• Methodologies for Conducting Education Research
• Mixed Methods Research
• Philosophy of Education
• Politics of Education
• Qualitative Data Analysis Techniques

Other Subject Areas

Forthcoming articles expand or collapse the "forthcoming articles" section.

• Black Women in Academia
• Girls' Education in the Developing World
• History of Education in Europe
• Find more forthcoming articles...
• Export Citations
• Share This Facebook LinkedIn Twitter

Literature Reviews by Lawrence A. Machi , Brenda T. McEvoy LAST REVIEWED: 27 October 2016 LAST MODIFIED: 27 October 2016 DOI: 10.1093/obo/9780199756810-0169

Literature reviews play a foundational role in the development and execution of a research project. They provide access to the academic conversation surrounding the topic of the proposed study. By engaging in this scholarly exercise, the researcher is able to learn and to share knowledge about the topic. The literature review acts as the springboard for new research, in that it lays out a logically argued case, founded on a comprehensive understanding of the current state of knowledge about the topic. The case produced provides the justification for the research question or problem of a proposed study, and the methodological scheme best suited to conduct the research. It can also be a research project in itself, arguing policy or practice implementation, based on a comprehensive analysis of the research in a field. The term literature review can refer to the output or the product of a review. It can also refer to the process of Conducting a Literature Review . Novice researchers, when attempting their first research projects, tend to ask two questions: What is a Literature Review? How do you do one? While this annotated bibliography is neither definitive nor exhaustive in its treatment of the subject, it is designed to provide a beginning researcher, who is pursuing an academic degree, an entry point for answering the two previous questions. The article is divided into two parts. The first four sections of the article provide a general overview of the topic. They address definitions, types, purposes, and processes for doing a literature review. The second part presents the process and procedures for doing a literature review. Arranged in a sequential fashion, the remaining eight sections provide references addressing each step of the literature review process. References included in this article were selected based on their ability to assist the beginning researcher. Additionally, the authors attempted to include texts from various disciplines in social science to present various points of view on the subject.

Novice researchers often have a misguided perception of how to do a literature review and what the document should contain. Literature reviews are not narrative annotated bibliographies nor book reports (see Bruce 1994 ). Their form, function, and outcomes vary, due to how they depend on the research question, the standards and criteria of the academic discipline, and the orthodoxies of the research community charged with the research. The term literature review can refer to the process of doing a review as well as the product resulting from conducting a review. The product resulting from reviewing the literature is the concern of this section. Literature reviews for research studies at the master’s and doctoral levels have various definitions. Machi and McEvoy 2016 presents a general definition of a literature review. Lambert 2012 defines a literature review as a critical analysis of what is known about the study topic, the themes related to it, and the various perspectives expressed regarding the topic. Fink 2010 defines a literature review as a systematic review of existing body of data that identifies, evaluates, and synthesizes for explicit presentation. Jesson, et al. 2011 defines the literature review as a critical description and appraisal of a topic. Hart 1998 sees the literature review as producing two products: the presentation of information, ideas, data, and evidence to express viewpoints on the nature of the topic, as well as how it is to be investigated. When considering literature reviews beyond the novice level, Ridley 2012 defines and differentiates the systematic review from literature reviews associated with primary research conducted in academic degree programs of study, including stand-alone literature reviews. Cooper 1998 states the product of literature review is dependent on the research study’s goal and focus, and defines synthesis reviews as literature reviews that seek to summarize and draw conclusions from past empirical research to determine what issues have yet to be resolved. Theoretical reviews compare and contrast the predictive ability of theories that explain the phenomenon, arguing which theory holds the most validity in describing the nature of that phenomenon. Grant and Booth 2009 identified fourteen types of reviews used in both degree granting and advanced research projects, describing their attributes and methodologies.

Bruce, Christine Susan. 1994. Research students’ early experiences of the dissertation literature review. Studies in Higher Education 19.2: 217–229.

DOI: 10.1080/03075079412331382057

A phenomenological analysis was conducted with forty-one neophyte research scholars. The responses to the questions, “What do you mean when you use the words literature review?” and “What is the meaning of a literature review for your research?” identified six concepts. The results conclude that doing a literature review is a problem area for students.

Cooper, Harris. 1998. Synthesizing research . Vol. 2. 3d ed. Thousand Oaks, CA: SAGE.

The introductory chapter of this text provides a cogent explanation of Cooper’s understanding of literature reviews. Chapter 4 presents a comprehensive discussion of the synthesis review. Chapter 5 discusses meta-analysis and depth.

Fink, Arlene. 2010. Conducting research literature reviews: From the Internet to paper . 3d ed. Los Angeles: SAGE.

The first chapter of this text (pp. 1–16) provides a short but clear discussion of what a literature review is in reference to its application to a broad range of social sciences disciplines and their related professions.

Grant, Maria J., and Andrew Booth. 2009. A typology of reviews: An analysis of 14 review types and associated methodologies. Health Information & Libraries Journal 26.2: 91–108. Print.

DOI: 10.1111/j.1471-1842.2009.00848.x

This article reports a scoping review that was conducted using the “Search, Appraisal, Synthesis, and Analysis” (SALSA) framework. Fourteen literature review types and associated methodology make up the resulting typology. Each type is described by its key characteristics and analyzed for its strengths and weaknesses.

Hart, Chris. 1998. Doing a literature review: Releasing the social science research imagination . London: SAGE.

Chapter 1 of this text explains Hart’s definition of a literature review. Additionally, it describes the roles of the literature review, the skills of a literature reviewer, and the research context for a literature review. Of note is Hart’s discussion of the literature review requirements for master’s degree and doctoral degree work.

Jesson, Jill, Lydia Matheson, and Fiona M. Lacey. 2011. Doing your literature review: Traditional and systematic techniques . Los Angeles: SAGE.

Chapter 1: “Preliminaries” provides definitions of traditional and systematic reviews. It discusses the differences between them. Chapter 5 is dedicated to explaining the traditional review, while Chapter 7 explains the systematic review. Chapter 8 provides a detailed description of meta-analysis.

Lambert, Mike. 2012. A beginner’s guide to doing your education research project . Los Angeles: SAGE.

Chapter 6 (pp. 79–100) presents a thumbnail sketch for doing a literature review.

Machi, Lawrence A., and Brenda T. McEvoy. 2016. The literature review: Six steps to success . 3d ed. Thousand Oaks, CA: Corwin.

The introduction of this text differentiates between a simple and an advanced review and concisely defines a literature review.

Ridley, Diana. 2012. The literature review: A step-by-step guide for students . 2d ed. Sage Study Skills. London: SAGE.

In the introductory chapter, Ridley reviews many definitions of the literature review, literature reviews at the master’s and doctoral level, and placement of literature reviews within the thesis or dissertation document. She also defines and differentiates literature reviews produced for degree-affiliated research from the more advanced systematic review projects.

back to top

Users without a subscription are not able to see the full content on this page. Please subscribe or login .

Oxford Bibliographies Online is available by subscription and perpetual access to institutions. For more information or to contact an Oxford Sales Representative click here .

• About Education »
• Meet the Editorial Board »
• Academic Achievement
• Academic Audit for Universities
• Academic Freedom and Tenure in the United States
• Action Research in Education
• Adjuncts in Higher Education in the United States
• Administrator Preparation
• Adolescence
• Advanced Placement and International Baccalaureate Courses
• Advocacy and Activism in Early Childhood
• African American Racial Identity and Learning
• Alaska Native Education
• Alternative Certification Programs for Educators
• Alternative Schools
• American Indian Education
• Animals in Environmental Education
• Art Education
• Artificial Intelligence and Learning
• Assessing School Leader Effectiveness
• Assessment, Behavioral
• Assessment, Educational
• Assessment in Early Childhood Education
• Assistive Technology
• Augmented Reality in Education
• Beginning-Teacher Induction
• Bilingual Education and Bilingualism
• Black Undergraduate Women: Critical Race and Gender Perspe...
• Blended Learning
• Case Study in Education Research
• Changing Professional and Academic Identities
• Character Education
• Children’s and Young Adult Literature
• Children's Beliefs about Intelligence
• Children's Rights in Early Childhood Education
• Citizenship Education
• Civic and Social Engagement of Higher Education
• Classroom Learning Environments: Assessing and Investigati...
• Classroom Management
• Coherent Instructional Systems at the School and School Sy...
• College Admissions in the United States
• College Athletics in the United States
• Community Relations
• Comparative Education
• Computer-Assisted Language Learning
• Computer-Based Testing
• Conceptualizing, Measuring, and Evaluating Improvement Net...
• Continuous Improvement and "High Leverage" Educational Pro...
• Counseling in Schools
• Critical Approaches to Gender in Higher Education
• Critical Perspectives on Educational Innovation and Improv...
• Critical Race Theory
• Crossborder and Transnational Higher Education
• Cross-National Research on Continuous Improvement
• Cross-Sector Research on Continuous Learning and Improveme...
• Cultural Diversity in Early Childhood Education
• Culturally Responsive Leadership
• Culturally Responsive Pedagogies
• Culturally Responsive Teacher Education in the United Stat...
• Curriculum Design
• Data Collection in Educational Research
• Data-driven Decision Making in the United States
• Deaf Education
• Desegregation and Integration
• Design Thinking and the Learning Sciences: Theoretical, Pr...
• Development, Moral
• Dialogic Pedagogy
• Digital Age Teacher, The
• Digital Citizenship
• Digital Divides
• Disabilities
• Distance Learning
• Distributed Leadership
• Doctoral Education and Training
• Early Childhood Education and Care (ECEC) in Denmark
• Early Childhood Education and Development in Mexico
• Early Childhood Education in Aotearoa New Zealand
• Early Childhood Education in Australia
• Early Childhood Education in China
• Early Childhood Education in Europe
• Early Childhood Education in Sub-Saharan Africa
• Early Childhood Education in Sweden
• Early Childhood Education Pedagogy
• Early Childhood Education Policy
• Early Childhood Education, The Arts in
• Early Childhood Mathematics
• Early Childhood Science
• Early Childhood Teacher Education
• Early Childhood Teachers in Aotearoa New Zealand
• Early Years Professionalism and Professionalization Polici...
• Economics of Education
• Education For Children with Autism
• Education for Sustainable Development
• Education Leadership, Empirical Perspectives in
• Education of Native Hawaiian Students
• Education Reform and School Change
• Educational Statistics for Longitudinal Research
• Educator Partnerships with Parents and Families with a Foc...
• Emotional and Affective Issues in Environmental and Sustai...
• Emotional and Behavioral Disorders
• English as an International Language for Academic Publishi...
• Environmental and Science Education: Overlaps and Issues
• Environmental Education
• Environmental Education in Brazil
• Epistemic Beliefs
• Equity and Improvement: Engaging Communities in Educationa...
• Equity, Ethnicity, Diversity, and Excellence in Education
• Ethical Research with Young Children
• Ethics and Education
• Ethics of Teaching
• Ethnic Studies
• Evidence-Based Communication Assessment and Intervention
• Family and Community Partnerships in Education
• Family Day Care
• Federal Government Programs and Issues
• Feminization of Labor in Academia
• Finance, Education
• Financial Aid
• Formative Assessment
• Future-Focused Education
• Gender and Achievement
• Gender and Alternative Education
• Gender, Power and Politics in the Academy
• Gender-Based Violence on University Campuses
• Gifted Education
• Global Mindedness and Global Citizenship Education
• Global University Rankings
• Governance, Education
• Grounded Theory
• Growth of Effective Mental Health Services in Schools in t...
• Higher Education and Globalization
• Higher Education and the Developing World
• Higher Education Faculty Characteristics and Trends in the...
• Higher Education Finance
• Higher Education Governance
• Higher Education Graduate Outcomes and Destinations
• Higher Education in Africa
• Higher Education in China
• Higher Education in Latin America
• Higher Education in the United States, Historical Evolutio...
• Higher Education, International Issues in
• Higher Education Management
• Higher Education Policy
• Higher Education Student Assessment
• High-stakes Testing
• History of Early Childhood Education in the United States
• History of Education in the United States
• History of Technology Integration in Education
• Homeschooling
• Inclusion in Early Childhood: Difference, Disability, and ...
• Inclusive Education
• Indigenous Education in a Global Context
• Indigenous Learning Environments
• Indigenous Students in Higher Education in the United Stat...
• Infant and Toddler Pedagogy
• Inservice Teacher Education
• Integrating Art across the Curriculum
• Intelligence
• Intensive Interventions for Children and Adolescents with ...
• International Perspectives on Academic Freedom
• Intersectionality and Education
• Knowledge Development in Early Childhood
• Leadership Development, Coaching and Feedback for
• Leadership in Early Childhood Education
• Leadership Training with an Emphasis on the United States
• Learning Analytics in Higher Education
• Learning Difficulties
• Learning, Lifelong
• Learning, Multimedia
• Learning Strategies
• Legal Matters and Education Law
• LGBT Youth in Schools
• Linguistic Diversity
• Linguistically Inclusive Pedagogy
• Literacy Development and Language Acquisition
• Literature Reviews
• Mathematics Identity
• Mathematics Instruction and Interventions for Students wit...
• Mathematics Teacher Education
• Measurement for Improvement in Education
• Measurement in Education in the United States
• Methodological Approaches for Impact Evaluation in Educati...
• Mindfulness, Learning, and Education
• Motherscholars
• Multiliteracies in Early Childhood Education
• Multiple Documents Literacy: Theory, Research, and Applica...
• Multivariate Research Methodology
• Museums, Education, and Curriculum
• Music Education
• Narrative Research in Education
• Native American Studies
• Nonformal and Informal Environmental Education
• Note-Taking
• Numeracy Education
• One-to-One Technology in the K-12 Classroom
• Online Education
• Open Education
• Organizing for Continuous Improvement in Education
• Organizing Schools for the Inclusion of Students with Disa...
• Outdoor Play and Learning
• Outdoor Play and Learning in Early Childhood Education
• Pedagogical Leadership
• Pedagogy of Teacher Education, A
• Performance Objectives and Measurement
• Performance-based Research Assessment in Higher Education
• Performance-based Research Funding
• Phenomenology in Educational Research
• Physical Education
• Podcasts in Education
• Policy Context of United States Educational Innovation and...
• Portable Technology Use in Special Education Programs and ...
• Post-humanism and Environmental Education
• Pre-Service Teacher Education
• Problem Solving
• Productivity and Higher Education
• Professional Development
• Professional Learning Communities
• Program Evaluation
• Programs and Services for Students with Emotional or Behav...
• Psychology Learning and Teaching
• Psychometric Issues in the Assessment of English Language ...
• Qualitative, Quantitative, and Mixed Methods Research Samp...
• Qualitative Research Design
• Quantitative Research Designs in Educational Research
• Queering the English Language Arts (ELA) Writing Classroom
• Race and Affirmative Action in Higher Education
• Reading Education
• Refugee and New Immigrant Learners
• Relational and Developmental Trauma and Schools
• Relational Pedagogies in Early Childhood Education
• Reliability in Educational Assessments
• Religion in Elementary and Secondary Education in the Unit...
• Researcher Development and Skills Training within the Cont...
• Research-Practice Partnerships in Education within the Uni...
• Response to Intervention
• Restorative Practices
• Risky Play in Early Childhood Education
• Scale and Sustainability of Education Innovation and Impro...
• Scaling Up Research-based Educational Practices
• School Accreditation
• School Choice
• School Culture
• School District Budgeting and Financial Management in the ...
• School Improvement through Inclusive Education
• School Reform
• Schools, Private and Independent
• School-Wide Positive Behavior Support
• Science Education
• Secondary to Postsecondary Transition Issues
• Self-Regulated Learning
• Self-Study of Teacher Education Practices
• Service-Learning
• Severe Disabilities
• Single Salary Schedule
• Single-sex Education
• Single-Subject Research Design
• Social Context of Education
• Social Justice
• Social Network Analysis
• Social Pedagogy
• Social Science and Education Research
• Social Studies Education
• Sociology of Education
• Standards-Based Education
• Statistical Assumptions
• Student Access, Equity, and Diversity in Higher Education
• Student Assignment Policy
• Student Engagement in Tertiary Education
• Student Learning, Development, Engagement, and Motivation ...
• Student Participation
• Student Voice in Teacher Development
• Sustainability Education in Early Childhood Education
• Sustainability in Early Childhood Education
• Sustainability in Higher Education
• Teacher Beliefs and Epistemologies
• Teacher Collaboration in School Improvement
• Teacher Evaluation and Teacher Effectiveness
• Teacher Preparation
• Teacher Training and Development
• Teacher Unions and Associations
• Teacher-Student Relationships
• Teaching Critical Thinking
• Technologies, Teaching, and Learning in Higher Education
• Technology Education in Early Childhood
• Technology, Educational
• Technology-based Assessment
• The Bologna Process
• The Regulation of Standards in Higher Education
• Theories of Educational Leadership
• Three Conceptions of Literacy: Media, Narrative, and Gamin...
• Tracking and Detracking
• Traditions of Quality Improvement in Education
• Transformative Learning
• Transitions in Early Childhood Education
• Tribally Controlled Colleges and Universities in the Unite...
• Understanding the Psycho-Social Dimensions of Schools and ...
• University Faculty Roles and Responsibilities in the Unite...
• Using Ethnography in Educational Research
• Value of Higher Education for Students and Other Stakehold...
• Virtual Learning Environments
• Vocational and Technical Education
• Wellness and Well-Being in Education
• Women's and Gender Studies
• Young Children and Spirituality
• Young Children's Learning Dispositions
• Young Children's Working Theories
• Privacy Policy
• Cookie Policy
• Legal Notice
• Accessibility

Powered by:

• [66.249.64.20|185.80.151.9]
• 185.80.151.9

Get science-backed answers as you write with Paperpal's Research feature

What is a Literature Review? How to Write It (with Examples)

A literature review is a critical analysis and synthesis of existing research on a particular topic. It provides an overview of the current state of knowledge, identifies gaps, and highlights key findings in the literature. 1 The purpose of a literature review is to situate your own research within the context of existing scholarship, demonstrating your understanding of the topic and showing how your work contributes to the ongoing conversation in the field. Learning how to write a literature review is a critical tool for successful research. Your ability to summarize and synthesize prior research pertaining to a certain topic demonstrates your grasp on the topic of study, and assists in the learning process. 

Table of Contents

• What is the purpose of literature review? 
• a. Habitat Loss and Species Extinction: 
• b. Range Shifts and Phenological Changes: 
• c. Ocean Acidification and Coral Reefs: 
• d. Adaptive Strategies and Conservation Efforts: 

How to write a good literature review 

• Choose a Topic and Define the Research Question: 
• Decide on the Scope of Your Review: 
• Select Databases for Searches: 
• Conduct Searches and Keep Track: 
• Review the Literature: 
• Organize and Write Your Literature Review: 
• How to write a literature review faster with Paperpal? 
• Frequently asked questions 

What is a literature review?

A well-conducted literature review demonstrates the researcher’s familiarity with the existing literature, establishes the context for their own research, and contributes to scholarly conversations on the topic. One of the purposes of a literature review is also to help researchers avoid duplicating previous work and ensure that their research is informed by and builds upon the existing body of knowledge.

What is the purpose of literature review?

A literature review serves several important purposes within academic and research contexts. Here are some key objectives and functions of a literature review: 2  

1. Contextualizing the Research Problem: The literature review provides a background and context for the research problem under investigation. It helps to situate the study within the existing body of knowledge. 

2. Identifying Gaps in Knowledge: By identifying gaps, contradictions, or areas requiring further research, the researcher can shape the research question and justify the significance of the study. This is crucial for ensuring that the new research contributes something novel to the field. 

Find academic papers related to your research topic faster. Try Research on Paperpal  

3. Understanding Theoretical and Conceptual Frameworks: Literature reviews help researchers gain an understanding of the theoretical and conceptual frameworks used in previous studies. This aids in the development of a theoretical framework for the current research. 

4. Providing Methodological Insights: Another purpose of literature reviews is that it allows researchers to learn about the methodologies employed in previous studies. This can help in choosing appropriate research methods for the current study and avoiding pitfalls that others may have encountered. 

5. Establishing Credibility: A well-conducted literature review demonstrates the researcher’s familiarity with existing scholarship, establishing their credibility and expertise in the field. It also helps in building a solid foundation for the new research. 

6. Informing Hypotheses or Research Questions: The literature review guides the formulation of hypotheses or research questions by highlighting relevant findings and areas of uncertainty in existing literature. 

Literature review example

Let’s delve deeper with a literature review example: Let’s say your literature review is about the impact of climate change on biodiversity. You might format your literature review into sections such as the effects of climate change on habitat loss and species extinction, phenological changes, and marine biodiversity. Each section would then summarize and analyze relevant studies in those areas, highlighting key findings and identifying gaps in the research. The review would conclude by emphasizing the need for further research on specific aspects of the relationship between climate change and biodiversity. The following literature review template provides a glimpse into the recommended literature review structure and content, demonstrating how research findings are organized around specific themes within a broader topic. 

Literature Review on Climate Change Impacts on Biodiversity:

Climate change is a global phenomenon with far-reaching consequences, including significant impacts on biodiversity. This literature review synthesizes key findings from various studies: 

a. Habitat Loss and Species Extinction:

Climate change-induced alterations in temperature and precipitation patterns contribute to habitat loss, affecting numerous species (Thomas et al., 2004). The review discusses how these changes increase the risk of extinction, particularly for species with specific habitat requirements. 

b. Range Shifts and Phenological Changes:

Observations of range shifts and changes in the timing of biological events (phenology) are documented in response to changing climatic conditions (Parmesan & Yohe, 2003). These shifts affect ecosystems and may lead to mismatches between species and their resources. 

c. Ocean Acidification and Coral Reefs:

The review explores the impact of climate change on marine biodiversity, emphasizing ocean acidification’s threat to coral reefs (Hoegh-Guldberg et al., 2007). Changes in pH levels negatively affect coral calcification, disrupting the delicate balance of marine ecosystems. 

d. Adaptive Strategies and Conservation Efforts:

Recognizing the urgency of the situation, the literature review discusses various adaptive strategies adopted by species and conservation efforts aimed at mitigating the impacts of climate change on biodiversity (Hannah et al., 2007). It emphasizes the importance of interdisciplinary approaches for effective conservation planning. 

Strengthen your literature review with factual insights. Try Research on Paperpal for free!    

Writing a literature review involves summarizing and synthesizing existing research on a particular topic. A good literature review format should include the following elements. 

Introduction: The introduction sets the stage for your literature review, providing context and introducing the main focus of your review. 

• Opening Statement: Begin with a general statement about the broader topic and its significance in the field. 
• Scope and Purpose: Clearly define the scope of your literature review. Explain the specific research question or objective you aim to address. 
• Organizational Framework: Briefly outline the structure of your literature review, indicating how you will categorize and discuss the existing research. 
• Significance of the Study: Highlight why your literature review is important and how it contributes to the understanding of the chosen topic. 
• Thesis Statement: Conclude the introduction with a concise thesis statement that outlines the main argument or perspective you will develop in the body of the literature review. 

Body: The body of the literature review is where you provide a comprehensive analysis of existing literature, grouping studies based on themes, methodologies, or other relevant criteria. 

• Organize by Theme or Concept: Group studies that share common themes, concepts, or methodologies. Discuss each theme or concept in detail, summarizing key findings and identifying gaps or areas of disagreement. 
• Critical Analysis: Evaluate the strengths and weaknesses of each study. Discuss the methodologies used, the quality of evidence, and the overall contribution of each work to the understanding of the topic. 
• Synthesis of Findings: Synthesize the information from different studies to highlight trends, patterns, or areas of consensus in the literature. 
• Identification of Gaps: Discuss any gaps or limitations in the existing research and explain how your review contributes to filling these gaps. 
• Transition between Sections: Provide smooth transitions between different themes or concepts to maintain the flow of your literature review. 

Write and Cite as you go with Paperpal Research. Start now for free.   

Conclusion: The conclusion of your literature review should summarize the main findings, highlight the contributions of the review, and suggest avenues for future research. 

• Summary of Key Findings: Recap the main findings from the literature and restate how they contribute to your research question or objective. 
• Contributions to the Field: Discuss the overall contribution of your literature review to the existing knowledge in the field. 
• Implications and Applications: Explore the practical implications of the findings and suggest how they might impact future research or practice. 
• Recommendations for Future Research: Identify areas that require further investigation and propose potential directions for future research in the field. 
• Final Thoughts: Conclude with a final reflection on the importance of your literature review and its relevance to the broader academic community. 

Conducting a literature review

Conducting a literature review is an essential step in research that involves reviewing and analyzing existing literature on a specific topic. It’s important to know how to do a literature review effectively, so here are the steps to follow: 1  

Choose a Topic and Define the Research Question:

• Select a topic that is relevant to your field of study. 
• Clearly define your research question or objective. Determine what specific aspect of the topic do you want to explore? 

Decide on the Scope of Your Review:

• Determine the timeframe for your literature review. Are you focusing on recent developments, or do you want a historical overview? 
• Consider the geographical scope. Is your review global, or are you focusing on a specific region? 
• Define the inclusion and exclusion criteria. What types of sources will you include? Are there specific types of studies or publications you will exclude? 

Select Databases for Searches:

• Identify relevant databases for your field. Examples include PubMed, IEEE Xplore, Scopus, Web of Science, and Google Scholar. 
• Consider searching in library catalogs, institutional repositories, and specialized databases related to your topic. 

Conduct Searches and Keep Track:

• Develop a systematic search strategy using keywords, Boolean operators (AND, OR, NOT), and other search techniques. 
• Record and document your search strategy for transparency and replicability. 
• Keep track of the articles, including publication details, abstracts, and links. Use citation management tools like EndNote, Zotero, or Mendeley to organize your references. 

Review the Literature:

• Evaluate the relevance and quality of each source. Consider the methodology, sample size, and results of studies. 
• Organize the literature by themes or key concepts. Identify patterns, trends, and gaps in the existing research. 
• Summarize key findings and arguments from each source. Compare and contrast different perspectives. 
• Identify areas where there is a consensus in the literature and where there are conflicting opinions. 
• Provide critical analysis and synthesis of the literature. What are the strengths and weaknesses of existing research? 

Organize and Write Your Literature Review:

• Literature review outline should be based on themes, chronological order, or methodological approaches. 
• Write a clear and coherent narrative that synthesizes the information gathered. 
• Use proper citations for each source and ensure consistency in your citation style (APA, MLA, Chicago, etc.). 
• Conclude your literature review by summarizing key findings, identifying gaps, and suggesting areas for future research. 

Whether you’re exploring a new research field or finding new angles to develop an existing topic, sifting through hundreds of papers can take more time than you have to spare. But what if you could find science-backed insights with verified citations in seconds? That’s the power of Paperpal’s new Research feature!  

How to write a literature review faster with Paperpal?

Paperpal, an AI writing assistant, integrates powerful academic search capabilities within its writing platform. With the Research feature, you get 100% factual insights, with citations backed by 250M+ verified research articles, directly within your writing interface with the option to save relevant references in your Citation Library. By eliminating the need to switch tabs to find answers to all your research questions, Paperpal saves time and helps you stay focused on your writing.   

Here’s how to use the Research feature:  

• Ask a question: Get started with a new document on paperpal.com. Click on the “Research” feature and type your question in plain English. Paperpal will scour over 250 million research articles, including conference papers and preprints, to provide you with accurate insights and citations. 
• Review and Save: Paperpal summarizes the information, while citing sources and listing relevant reads. You can quickly scan the results to identify relevant references and save these directly to your built-in citations library for later access. 
• Cite with Confidence: Paperpal makes it easy to incorporate relevant citations and references into your writing, ensuring your arguments are well-supported by credible sources. This translates to a polished, well-researched literature review. 

The literature review sample and detailed advice on writing and conducting a review will help you produce a well-structured report. But remember that a good literature review is an ongoing process, and it may be necessary to revisit and update it as your research progresses. By combining effortless research with an easy citation process, Paperpal Research streamlines the literature review process and empowers you to write faster and with more confidence. Try Paperpal Research now and see for yourself.  

Frequently asked questions

A literature review is a critical and comprehensive analysis of existing literature (published and unpublished works) on a specific topic or research question and provides a synthesis of the current state of knowledge in a particular field. A well-conducted literature review is crucial for researchers to build upon existing knowledge, avoid duplication of efforts, and contribute to the advancement of their field. It also helps researchers situate their work within a broader context and facilitates the development of a sound theoretical and conceptual framework for their studies.

Literature review is a crucial component of research writing, providing a solid background for a research paper’s investigation. The aim is to keep professionals up to date by providing an understanding of ongoing developments within a specific field, including research methods, and experimental techniques used in that field, and present that knowledge in the form of a written report. Also, the depth and breadth of the literature review emphasizes the credibility of the scholar in his or her field.  

Before writing a literature review, it’s essential to undertake several preparatory steps to ensure that your review is well-researched, organized, and focused. This includes choosing a topic of general interest to you and doing exploratory research on that topic, writing an annotated bibliography, and noting major points, especially those that relate to the position you have taken on the topic. 

Literature reviews and academic research papers are essential components of scholarly work but serve different purposes within the academic realm. 3 A literature review aims to provide a foundation for understanding the current state of research on a particular topic, identify gaps or controversies, and lay the groundwork for future research. Therefore, it draws heavily from existing academic sources, including books, journal articles, and other scholarly publications. In contrast, an academic research paper aims to present new knowledge, contribute to the academic discourse, and advance the understanding of a specific research question. Therefore, it involves a mix of existing literature (in the introduction and literature review sections) and original data or findings obtained through research methods. 

Literature reviews are essential components of academic and research papers, and various strategies can be employed to conduct them effectively. If you want to know how to write a literature review for a research paper, here are four common approaches that are often used by researchers.  Chronological Review: This strategy involves organizing the literature based on the chronological order of publication. It helps to trace the development of a topic over time, showing how ideas, theories, and research have evolved.  Thematic Review: Thematic reviews focus on identifying and analyzing themes or topics that cut across different studies. Instead of organizing the literature chronologically, it is grouped by key themes or concepts, allowing for a comprehensive exploration of various aspects of the topic.  Methodological Review: This strategy involves organizing the literature based on the research methods employed in different studies. It helps to highlight the strengths and weaknesses of various methodologies and allows the reader to evaluate the reliability and validity of the research findings.  Theoretical Review: A theoretical review examines the literature based on the theoretical frameworks used in different studies. This approach helps to identify the key theories that have been applied to the topic and assess their contributions to the understanding of the subject.  It’s important to note that these strategies are not mutually exclusive, and a literature review may combine elements of more than one approach. The choice of strategy depends on the research question, the nature of the literature available, and the goals of the review. Additionally, other strategies, such as integrative reviews or systematic reviews, may be employed depending on the specific requirements of the research.

The literature review format can vary depending on the specific publication guidelines. However, there are some common elements and structures that are often followed. Here is a general guideline for the format of a literature review:  Introduction:   Provide an overview of the topic.  Define the scope and purpose of the literature review.  State the research question or objective.  Body:   Organize the literature by themes, concepts, or chronology.  Critically analyze and evaluate each source.  Discuss the strengths and weaknesses of the studies.  Highlight any methodological limitations or biases.  Identify patterns, connections, or contradictions in the existing research.  Conclusion:   Summarize the key points discussed in the literature review.  Highlight the research gap.  Address the research question or objective stated in the introduction.  Highlight the contributions of the review and suggest directions for future research.

Both annotated bibliographies and literature reviews involve the examination of scholarly sources. While annotated bibliographies focus on individual sources with brief annotations, literature reviews provide a more in-depth, integrated, and comprehensive analysis of existing literature on a specific topic. The key differences are as follows: 

References 

• Denney, A. S., & Tewksbury, R. (2013). How to write a literature review.  Journal of criminal justice education ,  24 (2), 218-234. 
• Pan, M. L. (2016).  Preparing literature reviews: Qualitative and quantitative approaches . Taylor & Francis. 
• Cantero, C. (2019). How to write a literature review.  San José State University Writing Center . 

Paperpal is an AI writing assistant that help academics write better, faster with real-time suggestions for in-depth language and grammar correction. Trained on millions of research manuscripts enhanced by professional academic editors, Paperpal delivers human precision at machine speed.  

Try it for free or upgrade to  Paperpal Prime , which unlocks unlimited access to premium features like academic translation, paraphrasing, contextual synonyms, consistency checks and more. It’s like always having a professional academic editor by your side! Go beyond limitations and experience the future of academic writing.  Get Paperpal Prime now at just US$19 a month!

Related Reads:

• Empirical Research: A Comprehensive Guide for Academics 
• How to Write a Scientific Paper in 10 Steps 
• How Long Should a Chapter Be?
• How to Use Paperpal to Generate Emails & Cover Letters?

6 Tips for Post-Doc Researchers to Take Their Career to the Next Level

Self-plagiarism in research: what it is and how to avoid it, you may also like, how to ace grant writing for research funding..., how to write a high-quality conference paper, how paperpal’s research feature helps you develop and..., how paperpal is enhancing academic productivity and accelerating..., how to write a successful book chapter for..., academic editing: how to self-edit academic text with..., 4 ways paperpal encourages responsible writing with ai, what are scholarly sources and where can you..., how to write a hypothesis types and examples , measuring academic success: definition & strategies for excellence.

Communication Studies *: The Literature Review

• Electronic Books
• Citation Tracking
• Conference Proceedings & White Papers
• Find the Full Text
• Broadcasts/Transcripts/Speeches
• Latino Newspapers
• Current News
• General Statistics
• Public Opinion
• Market Research
• Company Research
• Online videos
• Tests/Measures
• DVD Collection
• More Guides
• Research Tools
• RefWorks 2.0
• RefWorks 2.0 Tutorials
• Evaluating Sources
• Primary Sources
• Secondary Sources
• Tiertiary Sources
• What Is Scholarly vs. Popular?
• Databases for Literature Review
• Government Websites

A literature review surveys scholarly articles, books and other sources relevant to a particular issue, area of research, or theory, and by so doing, providing a description, summary, and critical evaluation of these works. Literature reviews are designed to provide an overview of sources you have explored while researching a particular topic and to demonstrate to your readers how your research fits into the larger field of study.

All contect is from a Literature Review please refer to the sub-tab under The Literature Review created by Dr. Robert Larabee.

Importance of a Good Literature Review

A literature review may consist of simple a summary of key sources, but it usually has an organizational pattern and combines both summary and synthesis, often within specific conceptual categories . A summary is a recap of the important information of the source, but a synthesis is a re-organization, or a reshuffling, of that information in a way that informs how you are planning to investigate a research problem. The analytical features of a literature review might:

• give a new interpretation of old material or combine new with old interpretations,
• trace the intellectual progression of the field, including major debates,
• depending on the situation, evaluate the sources and advise the reader on the most pertinent or relevant, or
• usually in the conclusion of a literature review, identify where gaps exist in how a problem has been researched to date.

The purpose of a literature review is to:

• Place each work in the context of its contribution to the understanding of the research problem being studied,
• Describe the relationship of each work to the others under consideration,
• Identify new ways to interpret, and shed light on any gaps in previous research,
• Resolve conflicts amongst seemingly contradictory previous studies,
• Identify areas of prior scholarship to prevent duplication of effort,
• Point the way in fulfilling a need for additional research, and
• Locate your own research within the context of existing literature.

All contect is from The Literature Review created by Dr. Robert Larabee.

Types of Literature Reviews

As Kennedy (2007) notes*, it is important to think of knowledge in a given field as consisting of three layers. First, there are the primary studies that researchers conduct and publish. Second are the reviews of those studies that summarize and offer new interpretations built from and often extending beyond the original studies. Third, there are the perceptions, conclusions, opinion, and interpretations that are shared informally that become part of the lore of field. In composing a literature review, it is important to note that it is often this third layer of knowledge that is cited as "true" even though it often has only a loose relationship to the primary studies and secondary literature reviews.

Given this, while literature reviews are designed to provide an overview and synthesis of pertinent sources you have explored, there are several approaches to how they can be done, depending upon the type of analysis underpinning your study. Listed below are definitions of types of literature reviews:

Argumentative Review      This form examines literature selectively in order to support or refute an argument, deeply imbedded assumption, or philosophical problem already established in the literature. The purpose is to develop a body of literature that establishes a contrarian viewpoint. Given the value-laden nature of some social science research [e.g., educational reform; immigration control], argumentative approaches to analyzing the literature can be a legitimate and important form of discourse. However, note that they can also introduce problems of bias when they are used to to make summary claims of the sort found in systematic reviews.

Integrative Review      Considered a form of research that reviews, critiques, and synthesizes representative literature on a topic in an integrated way such that new frameworks and perspectives on the topic are generated. The body of literature includes all studies that address related or identical hypotheses. A well-done integrative review meets the same standards as primary research in regard to clarity, rigor, and replication.

Historical Review      Few things rest in isolation from historical precedent. Historical reviews are focused on examining research throughout a period of time, often starting with the first time an issue, concept, theory, phenomena emerged in the literature, then tracing its evolution within the scholarship of a discipline. The purpose is to place research in a historical context to show familiarity with state-of-the-art developments and to identify the likely directions for future research.

Methodological Review      A review does not always focus on what someone said [content], but how they said it [method of analysis]. This approach provides a framework of understanding at different levels (i.e. those of theory, substantive fields, research approaches and data collection and analysis techniques), enables researchers to draw on a wide variety of knowledge ranging from the conceptual level to practical documents for use in fieldwork in the areas of ontological and epistemological consideration, quantitative and qualitative integration, sampling, interviewing, data collection and data analysis, and helps highlight many ethical issues which we should be aware of and consider as we go through our study.

Systematic Review      This form consists of an overview of existing evidence pertinent to a clearly formulated research question, which uses pre-specified and standardized methods to identify and critically appraise relevant research, and to collect, report, and analyse data from the studies that are included in the review. Typically it focuses on a very specific empirical question, often posed in a cause-and-effect form, such as "To what extent does A contribute to B?"

Theoretical Review      The purpose of this form is to concretely examine the corpus of theory that has accumulated in regard to an issue, concept, theory, phenomena. The theoretical literature review help establish what theories already exist, the relationships between them, to what degree the existing theories have been investigated, and to develop new hypotheses to be tested. Often this form is used to help establish a lack of appropriate theories or reveal that current theories are inadequate for explaining new or emerging research problems. The unit of analysis can focus on a theoretical concept or a whole theory or framework.

* Kennedy, Mary M. "Defining a Literature." Educational Researcher 36 (April 2007): 139-147.

Structure and Writing Style

I.  Thinking About Your Literature Review

The structure of a literature review should include the following :

• An overview of the subject, issue or theory under consideration, along with the objectives of the literature review,
• Division of works under review into themes or categories (e.g. works that support of a particular position, those against, and those offering alternative approaches entirely),
• An explanation of how each work is similar to and how it varies from the others,
• Conclusions as to which pieces are best considered in their argument, are most convincing of their opinions, and make the greatest contribution to the understanding and development of their area of research

The critical evaluation of each work should consider :

• Provenance -- what are the author's credentials? Are the author's arguments supported by evidence (e.g. primary historical material, case studies, narratives, statistics, recent scientific findings)?
• Objectivity -- is the author's perspective even-handed or prejudicial? Is contrary data considered or is certain pertinent information ignored to prove the author's point?
• Persuasiveness -- which of the author's theses are most/least convincing?
• Value -- are the author's arguments and conclusions convincing? Does the work ultimately contribute in any significant way to an understanding of the subject?

II.  The Development of the Literature Review

Four stages : 1.  Problem formulation -- which topic or field is being examined and what are its component issues? 2.  Literature search -- finding materials relevant to the subject being explored. 3.  Data evaluation -- determining which literature makes a significant contribution to the understanding of the topic. 4.  Analysis and interpretation -- discussing the findings and conclusions of pertinent literature.

Consider the following issues before writing the literature review: Clarify If your assignment is not very specific about what form your literature review should take, seek clarification from your professor by asking these questions: 1.  Roughly how many sources should I include? 2.  What types of sources should I review (books, journal articles, websites)? 3.  Should I summarize, synthesize, or critique your sources by discussing a common theme or issue? 4.  Should I evaluate the sources? 5.  Should I provide subheadings and other background information, such as definitions and/or a history? Find Models Use the exercise of reviewing the literature to examine how authors in your discipline or area of interest have composed their literature reviews. Read them to get a sense of the types of themes you might want to look for in your own research or ways to organize your final review. The bibliography or reference section of sources you've already read are also excellent entry points into your own research. Narrow the Topic The narrower your topic, the easier it will be to limit the number of sources you need to read in order to obtain a good survey of relevant resources. Your professor will probably not expect you to read everything that's available about the topic, but you'll make your job easier if you first limit scope of the research problem. A good strategy is to begin by searching the HOMER catalog for books about the topic and review their contents for chapters that focus on more specific issues. You can also review the subject indexes of books to find references to specific issues that can serve as the focus of your research. For example, a book surveying the history of the Israeli-Palestinian conflict may include a chapter on the role Egypt has played in mediating the conflict. Consider Whether Your Sources are Current Some disciplines require that you use information that is as current as possible. This is very common in the sciences where research conducted only two years ago could be obsolete. However, when writing a review in the social sciences, a survey of the history of the literature may be what is needed because what is important is how perspectives have changed over the years or within a certain time period. Try sorting through some other current bibliographies or literature reviews in the field to get a sense of what your discipline expects. You can also use this method to consider what is consider by scholars to be a "hot topic" and what is not.

III.  Ways to Organize Your Literature Review

Chronological of Events If your review follows the chronological method, you could write about the materials according to when they were published. This approach should only be followed if a clear path of research building on previous research can be identified and that these trends follow a clear chronological order of development. For example, a literature review that focuses on continuing research about the emergence of German economic power after the fall of the Soviet Union. By Publication Order your sources by publication chronology, then, only if the order demonstrates a more important trend. For instance, you could order a review of literature on environmental studies of brown fields if the progression of revealed a change in the soil collection practices of the researchers who wrote and/or conducted the studies. Thematic (“conceptual categories”) Thematic reviews of literature are organized around a topic or issue, rather than the progression of time. However, progression of time may still be an important factor in a thematic review. For example, a review of the Internet’s impact on American presidential politics could focus on the development of online political satire. While the study focuses on one topic, the Internet’s impact on American presidential politics, it will still be organized chronologically reflecting technological developments in media. The only difference here between a "chronological" and a "thematic" approach is what is emphasized the most: the role of the Internet in presidential politics. Note however that more authentic thematic reviews tend to break away from chronological order. A review organized in this manner would shift between time periods within each section according to the point made. Methodological A methodological approach focuses on the methods utilized by the researcher. For the Interbnet in American presidential politics project, one methodological approach would be to look at cultural differences between the portrayal of American presidents on American, British, and French websites. Or the review might focus on the fundraising impact of the Internet on a particular political party. A methodological scope will influence either the types of documents in the review or the way in which these documents are discussed.

Other Sections of Your Literature Review Once you've decided on the organizational method for your literature review, the sections you need to include in the paper should be easy to figure out because they arise from your organizational strategy. In other words, a chronological review would have subsections for each vital time period; a thematic review would have subtopics based upon factors that relate to the theme or issue. However, sometimes you may need to add additional sections that are necessary for your study, but do not fit in the organizational strategy of the body. What other sections you include in the body is up to you but include only what is necessary for the reader to locate your study within the larger scholarship framework.

Here are examples of other sections you may need to include depending on the type of review you write:

• Current Situation : information necessary to understand the topic or focus of the literature review.
• History : the chronological progression of the field, the literature, or an idea that is necessary to understand the literature review, if the body of the literature review is not already a chronology.
• Selection Methods : the criteria you used to select (and perhaps exclude) sources in your literature review. For instance, you might explain that your review includes only peer-reviewed articles and journals.
• Standards : the way in which you present your information.
• Questions for Further Research : What questions about the field has the review sparked? How will you further your research as a result of the review?

IV.  Writing Your Literature Review

Once you've settled on how to organize your literature review, you're ready to write each section. When writing your review, keep in mind these issues.

Use Evidence A literature review in this sense is just like any other academic research paper. Your interpretation of the available sources must be backed up with evidence to show that what you are saying is valid. Be Selective Select only the most important points in each source to highlight in the review. The type of information you choose to mention should relate directly to the research problem, whether it is thematic, methodological, or chronological. Use Quotes Sparingly Some short quotes are okay if you want to emphasize a point, or if what the author said just cannot be rewritten in your own words. Sometimes you may need to quote certain terms that were coined by the author, not common knowledge, or taken directly from the study. Do not use extensive quotes as a substitute your own summary and interpretation of the literature. Summarize and Synthesize Remember to summarize and synthesize your sources within each paragraph as well as throughout the review. Recapitulate important features of a research study, but then synthesize it by rephrasing the study's significance and relating it to their own work. Keep Your Own Voice While the literature review presents others' ideas, your voice (the writer's) should remain front and center. For example, weave references to other sources into what you are writing but maintain your own voice by starting and ending the paragraph with your own ideas and wording. Use Caution When Paraphrasing When paraphrasing a source that is not your own, be sure to represent the author's information or opinions accurately and in your own words. Even when paraphrasing an author’s work, you still must provide a citation to that work.

V.  Common Mistakes to Avoid

The most common mistakes made in reviewing social science research literature are that the researcher:

• does not clearly relate the findings of the literature review to the research problem;
• does not take sufficient time to define and identify the most relevent sources to use in the literature review related to the research problem;
• relies exclusively on secondary analytical sources rather than including primary research studies or data;
• uncritically accepts another researcher's findings and interpretations as valid, rather than examining critically all aspects of the research design and analysis;
• does not describe the search procedures that were used in the literature review;
• reports isolated statistical results rather than sythesizing them in chi-squared or meta-analytic methods; and,
• only includes research that validates assumptions and does not consider contrary findings and alternative interpretations found in the literature.

Writing Tip

Break Out of Your Disciplinary Box!

Thinking interdisciplinarily about a research problem can be a rewarding exercise in applying new ideas, theories, or concepts to an old problem. For example, what might cultural anthropologists say about the continuing conflict in the Middle East? In what ways might geographers view the need for better distribution of social service agencies in large cities than how social workers might study the issue? You don’t want to substitute a thorough review of core research literature in your discipline for studies conducted in other fields of study. However, particularly in the social sciences, thinking about research problems from multiple vectors is a key strategy for finding new solutions. Consult with a librarian about identifying research databases in other disciplines; almost every discipline has at least one comprehensive database devoted to indexing its research literature.

Another Writing Tip

Don't Just Review for Content!

While conducting a review of the literature, maximize the time you devote to this part of writing a research paper by thinking broadly about what you should be looking for and evaluating. Review not just what scholars are saying, but how are they saying it. How are they structuring their ideas? What methods have they used to study the problem? What sources have they cited to support of their conclusions? How have they used non-textual elements [e.g., charts, graphs, figures, etc.] to illustrate key points?

Yet Another Writing Tip

When Do I Know I Can Stop Looking and Move On?

Here are several strategies you can utilize to assess whether you've adequately reviewed the research literature:

• Look for repeating patterns in the research findings . If the same thing is being said, just by different people, then this likely demonstrates that the research problem has hit a dead end. At this point consider: Does your study extend current research?  Does it forge as new path? Or, does is merely add more of the same thing being said?
• Look at the sources authors cite to in their work . If you begin to see the same researchers cited again and again, then this is often an indication that no new ideas have been introduced to the research question.
• Search the World of Knowledge Citation database and Google Scholar to identify who has subsequently cited leading scholars already identified in your literature review. This is called citation tracking and there are a number of sources that can help you identify who has cited whom, particularly scholars from outside of your discipline.
• << Previous: Ratings
• Next: Citation Tracking >>
• Last Updated: Feb 23, 2024 2:44 PM
• URL: https://libguides.usc.edu/communication

An official website of the United States government

The .gov means it’s official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

• Publications
• Account settings

Preview improvements coming to the PMC website in October 2024. Learn More or Try it out now .

• Advanced Search
• Journal List
• J Mark Access Health Policy
• v.11(1); 2023
• PMC10392303

Rapid literature review: definition and methodology

Beata smela.

a Assignity, Cracow, Poland

Mondher Toumi

b Public Health Department, Aix-Marseille University, Marseille, France

Karolina Świerk

Clement francois, małgorzata biernikiewicz.

c Studio Slowa, Wroclaw, Poland

Emilie Clay

d Clever-Access, Paris, France

Laurent Boyer

Introduction: A rapid literature review (RLR) is an alternative to systematic literature review (SLR) that can speed up the analysis of newly published data. The objective was to identify and summarize available information regarding different approaches to defining RLR and the methodology applied to the conduct of such reviews.

Methods: The Medline and EMBASE databases, as well as the grey literature, were searched using the set of keywords and their combination related to the targeted and rapid review, as well as design, approach, and methodology. Of the 3,898 records retrieved, 12 articles were included.

Results: Specific definition of RLRs has only been developed in 2021. In terms of methodology, the RLR should be completed within shorter timeframes using simplified procedures in comparison to SLRs, while maintaining a similar level of transparency and minimizing bias. Inherent components of the RLR process should be a clear research question, search protocol, simplified process of study selection, data extraction, and quality assurance.

Conclusions: There is a lack of consensus on the formal definition of the RLR and the best approaches to perform it. The evidence-based supporting methods are evolving, and more work is needed to define the most robust approaches.

Introduction

A systematic literature review (SLR) summarizes the results of all available studies on a specific topic and provides a high level of evidence. Authors of the SLR have to follow an advanced plan that covers defining a priori information regarding the research question, sources they are going to search, inclusion criteria applied to choose studies answering the research question, and information regarding how they are going to summarize findings [ 1 ].

The rigor and transparency of SLRs make them the most reliable form of literature review [ 2 ], providing a comprehensive, objective summary of the evidence for a given topic [ 3 , 4 ]. On the other hand, the SLR process is usually very time-consuming and requires a lot of human resources. Taking into account a high increase of newly published data and a growing need to analyze information in the fastest possible way, rapid literature reviews (RLRs) often replace standard SLRs.

There are several guidelines on the methodology of RLRs [ 5–11 ]; however, only recently, one publication from 2021 attempted to construct a unified definition [ 11 ]. Generally, by RLRs, researchers understand evidence synthesis during which some of the components of the systematic approach are being used to facilitate answering a focused research question; however, scope restrictions and a narrower search strategy help to make the project manageable in a shorter time and to get the key conclusions faster [ 4 ].

The objective of this research was to collect and summarize available information on different approaches to the definition and methodology of RLRs. An RLR has been run to capture publications providing data that fit the project objective.

To find publications reporting information on the methodology of RLRs, searches were run in the Medline and EMBASE databases in November 2022. The following keywords were searched for in titles and abstracts: ‘targeted adj2 review’ OR ‘focused adj2 review’ OR ‘rapid adj2 review’, and ‘methodology’ OR ‘design’ OR ‘scheme’ OR ‘approach’. The grey literature was identified using Google Scholar with keywords including ‘targeted review methodology’ OR ‘focused review methodology’ OR ‘rapid review methodology’. Only publications in English were included, and the date of publication was restricted to year 2016 onward in order to identify the most up-to-date literature. The reference lists of each included article were searched manually to obtain the potentially eligible articles. Titles and abstracts of the retrieved records were first screened to exclude articles that were evidently irrelevant. The full texts of potentially relevant papers were further reviewed to examine their eligibility.

A pre-defined Excel grid was developed to extract the following information related to the methodology of RLR from guidelines:

• Definition,
• Research question and searches,
• Studies selection,
• Data extraction and quality assessment,
• Additional information.

There was no restriction on the study types to be analyzed; any study reporting on the methodology of RLRs could be included: reviews, practice guidelines, commentaries, and expert opinions on RLR relevant to healthcare policymakers or practitioners. The data extraction and evidence summary were conducted by one analyst and further examined by a senior analyst to ensure that relevant information was not omitted. Disagreements were resolved by discussion and consensus.

Studies selection

A total of 3,898 records (3,864 articles from a database search and 34 grey literature from Google Scholar) were retrieved. After removing duplicates, titles and abstracts of 3,813 articles were uploaded and screened. The full texts of 43 articles were analyzed resulting in 12 articles selected for this review, including 7 guidelines [ 5–11 ] on the methodology of RLRs, together with 2 papers summarizing the results of the Delphi consensus on the topic [ 12 , 13 ], and 3 publications analyzing and assessing different approaches to RLRs [ 4 , 14 , 15 ].

Overall, seven guidelines were identified: from the World Health Organization (WHO) [ 5 ], National Collaborating Centre for Methods and Tools (NCCMT) [ 7 ], the UK government [ 8 ], the Oxford Centre for Evidence Based Medicine [ 9 ], the Cochrane group [ 6 , 11 ], and one multi-national review [ 10 ]. Among the papers that did not describe the guidelines, Gordon et al. [ 4 ] proposed 12 tips for conducting a rapid review in the right settings and discussed why these reviews may be more beneficial in some circumstances. The objective of work conducted by Tricco et al. [ 13 ] and Pandor et al. [ 12 ] was to collect and compare perceptions of rapid reviews from stakeholders, including researchers, policymakers, industry, journal editors, and healthcare providers, and to reach a consensus outlining the domains to consider when deciding on approaches for RLRs. Haby et al. [ 14 ] run a rapid review of systematic reviews and primary studies to find out the best way to conduct an RLR in health policy and practice. In Tricco et al. (2022) [ 15 ], JBI position statement for RLRs is presented.

From all the seven identified guidelines information regarding definitions the authors used for RLRs, approach to the PICOS criteria and search strategy development, studies selection, data extractions, quality assessment, and reporting were extracted.

Cochrane Rapid Reviews Methods Group developed methods guidance based on scoping review of the underlying evidence, primary methods studies conducted, as well as surveys sent to Cochrane representative and discussion among those with expertise [ 11 ]. They analyzed over 300 RLRs or RLR method papers and based on the methodology of those studies, constructed a broad definition RLR, one that meets a minimum set of requirements identified in the thematic analysis: ‘ A rapid review is a form of knowledge synthesis that accelerates the process of conducting a traditional systematic review through streamlining or omitting a variety of methods to produce evidence in a resource-efficient manner .’ This interpretation aligns with more than 50% of RLRs identified in this study. The authors additionally provided several other definitions, depending on specific situations or requirements (e.g., when RLR is produced on stakeholder’s request). It was additionally underlined that RLRs should be driven by the need of timely evidence for decision-making purposes [ 11 ].

Rapid reviews vary in their objective, format, and methods used for evidence synthesis. This is a quite new area, and still no agreement on optimal methods can be found [ 5 ]. All of the definitions are highlighting that RLRs are completed within shorter timeframes than SLRs, and also lack of time is one of the main reasons they are conducted. It has been suggested that most rapid reviews are conducted within 12 weeks; however, some of the resources suggest time between a few weeks to no more than 6 months [ 5 , 6 ]. Some of the definitions are highlighting that RLRs follow the SLR process, but certain phases of the process are simplified or omitted to retrieve information in a time-saving way [ 6 , 7 ]. Different mechanisms are used to enhance the timeliness of reviews. They can be used independently or concurrently: increasing the intensity of work by intensifying the efforts of multiple analysts by parallelization of tasks, using review shortcuts whereby one or more systematic review steps may be reduced, automatizing review steps by using new technologies [ 5 ]. The UK government report [ 8 ] referred to two different RLRs: in the form of quick scoping reviews (QSR) or rapid evidence assessments (REA). While being less resource and time-consuming compared to standard SLRs, QSRs and REAs are designed to be similarly transparent and to minimize bias. QSRs can be applied to rather open-ended questions, e.g., ‘what do we know about something’ but both, QSRs and REAs, provide an understanding of the volume and characteristics of evidence on a specific topic, allowing answering questions by maximizing the use of existing data, and providing a clear picture of the adequacy of existing evidence [ 8 ].

Research questions and searches

The guidelines suggest creating a clear research question and search protocol at the beginning of the project. Additionally, to not duplicate RLRs, the Cochrane Rapid Reviews Methods Group encourages all people working on RLRs to consider registering their search protocol with PROSPERO, the international prospective register of reviews; however, so far they are not formally registered in most cases [ 5 , 6 ]. They also recommend involving key stakeholders (review users) to set and refine the review question, criteria, and outcomes, as well as consulting them through the entire process [ 11 ].

Regarding research questions, it is better to structure them in a neutral way rather than focus on a specific direction for the outcome. By doing so, the researcher is in a better position to identify all the relevant evidence [ 7 ]. Authors can add a second, supportive research question when needed [ 8 ]. It is encouraged to limit the number of interventions, comparators and outcomes, to focus on the ones that are most important for decision-making [ 11 ]. Useful could be also reviewing additional materials, e.g., SLRs on the topic, as well as conducting a quick literature search to better understand the topic before starting with RLRs [ 7 ]. In SLRs researchers usually do not need to care a lot about time spent on creating PICOS, they need to make sure that the scope is broad enough, and they cannot use many restrictions. When working on RLRs, a reviewer may spend more or less time defining each of the components of the study question, and the main step is making sure that PICOS addresses the needs of those who requested the rapid review, and at the same time, it is feasible within the required time frame [ 7 ]. Search protocol should contain an outline of how the following review steps are to be carried out, including selected search keywords and a full strategy, a list of data sources, precise inclusion and exclusion criteria, a strategy for data extraction and critical appraisal, and a plan of how the information will be synthesized [ 8 ].

In terms of searches running, in most cases, an exhaustive process will not be feasible. Researchers should make sure that the search is effective and efficient to produce results in a timely manner. Cochrane Rapid Reviews Methods Group recommends involving an information specialist and conducting peer review of at least one search strategy [ 11 ]. According to the rapid review guidebook by McMaster University [ 7 ], it is important that RLRs, especially those that support policy and program decisions, are being fed by the results of a body of literature, rather than single studies, when possible. It would result in more generalizable findings applied at the level of a population and serve more realistic findings for program decisions [ 7 ]. It is important to document the search strategy, together with a record of the date and any date limits of the search, so that it can easily be run again, modified, or updated. Furthermore, the information on the individual databases included in platform services should always be reported, as this depends on organizations’ subscriptions and must be included for transparency and repeatability [ 7 , 8 ]. Good solution for RLRs is narrowing the scope or searching a limited number of databases and other sources [ 7 ]. Often, the authors use the PubMed/MEDLINE, Cochrane Library, and Embase databases. In most reviews, two or more databases are searched, and common limits are language (usually restricted to English), date, study design, and geographical area. Some RLRs include searching of grey literature; however, contact with authors is rather uncommon [ 5 , 8 ]. According to the flexible framework for restricted systematic review published by the University of Oxford, the search should be run in at least one major scientific database such as PubMed, and one other source, e.g., Google Scholar [ 9 ]. Grey literature and unpublished evidence may be particularly needed and important for intervention questions. It is related to the fact that studies that do not report the effects of interventions are less likely to be published [ 8 ]. If there is any type of evidence that will not be considered by the RLRs, e.g., reviews or theoretical and conceptual studies, it should also be stated in the protocol together with justification [ 8 ]. Additionally, authors of a practical guide published by WHO suggest using a staged search to identify existing SLRs at the beginning, and then focusing on studies with other designs [ 5 ]. If a low number of citations have been retrieved, it is acceptable to expand searches, remove some of the limits, and add additional databases and sources [ 7 ].

Searching for RLRs is an iterative process, and revising the approach is usually needed [ 7 ]. Changes should be confirmed with stakeholders and should be tracked and reflected in the final report [ 5 ].

The next step in the rapid review is the selection of studies consisting of two phases: screening of titles and abstracts, and analysis of full texts. Prior to screening initiation, it is recommended to conduct a pilot exercise using the same 30–50 abstracts and 5–10 full-texts for the entire screening team in order to calibrate and test the review form [ 11 ]. In contrast to SLRs, it can be done by one reviewer with or without verification by a second one. If verification is performed, usually the second reviewer checks only a subset of records and compares them. Cochrane Group, in contrast, recommends a stricter approach: at least 20% of references should be double-screened at titles and abstracts stage, and while the rest of the references may be screened by one reviewer, the excluded items need to be re-examined by second reviewer; similar approach is used in full-text screening [ 11 ]. This helps to ensure that bias was reduced and that the PICOS criteria are applied in a relevant way [ 5 , 8 , 9 , 11 ]. During the analysis of titles and abstracts, there is no need to report reasons for exclusion; however, they should be tracked for all excluded full texts [ 7 ].

Data extraction and quality assessment

According to the WHO guide, the most common method for data extraction in RLRs is extraction done by a single reviewer with or without partial verification. The authors point out that a reasonable approach is to use a second reviewer to check a random sample of at least 10% of the extractions for accuracy. Dual performance is more necessary for the extraction of quantitative results than for descriptive study information. In contrast, Cochrane group recommends that second reviewer should check the correctness and completeness of all data [ 11 ]. When possible, extractions should be limited to key characteristics and outcomes of the study. The same approach to data extraction is also suggested for a quality assessment process within rapid reviews [ 5 , 9 , 11 ]. Authors of the guidebook from McMaster University highlight that data extraction should be done ideally by two reviewers independently and consensus on the discrepancies should always be reached [ 7 ]. The final decision on the approach to this important step of review should depend on the available time and should also reflect the complexity of the research question [ 9 ].

For screening, analysis of full texts, extractions, and quality assessments, researchers can use information technologies to support them by making these review steps more efficient [ 5 ].

Before data reporting, a reviewer should prepare a document with key message headings, executive summary, background related to the topic and status of the current knowledge, project question, synthesis of findings, conclusions, and recommendations. According to the McMaster University guidebook, a report should be structured in a 1:2:20 format, that is, one page for key messages, two pages for an executive summary, and a full report of up to 20 pages [ 7 ]. All the limitations of the RLRs should be analyzed, and conclusions should be drawn with caution [ 5 ]. The quality of the accumulated evidence and the strength of recommendations can be assessed using, e.g., the GRADE system [ 5 ]. When working on references quoting, researchers should remember to use a primary source, not secondary references [ 7 ]. It would be worth considering the support of some software tools to automate reporting steps. Additionally, any standardization of the process and the usage of templates can support report development and enhance the transparency of the review [ 5 ].

Ideally, all the review steps should be completed during RLRs; however, often some steps may need skipping or will not be completed as thoroughly as should because of time constraints. It is always crucial to decide which steps may be skipped, and which are the key ones, depending on the project [ 7 ]. Guidelines suggest that it may be helpful to invite researchers with experience in the operations of SLRs to participate in the rapid review development [ 5 , 9 ]. As some of the steps will be completed by one reviewer only, it is important to provide them with relevant training at the beginning of the process, as well as during the review, to minimize the risk of mistakes [ 5 ].

Additional information

Depending on the policy goal and available resources and deadlines, methodology of the RLRs may be modified. Wilson et al. [ 10 ] provided extensive guidelines for performing RLR within days (e.g., to inform urgent internal policy discussions and/or management decisions), weeks (e.g., to inform public debates), or months (e.g., to inform policy development cycles that have a longer timeline, but that cannot wait for a traditional full systematic review). These approaches vary in terms of data synthesis, types of considered evidence and project management considerations.

In shortest timeframes, focused questions and subquestions should be formulated, typically to conduct a policy analysis; the report should consist of tables along with a brief narrative summary. Evidence from SLRs is often considered, as well as key informant interviews may be conducted to identify additional literature and insights about the topic, while primary studies and other types of evidence are not typically feasible due to time restrictions. The review would be best conducted with 1–2 reviewers sharing the work, enabling rapid iterations of the review. As for RLRs with longer timeline (weeks), these may use a mix of policy, systems and political analysis. Structure of the review would be similar to shorter RLRs – tabular with short narrative summary, as the timeline does not allow for comprehensive synthesis of data. Besides SLRs, primary studies and other evidence may be feasible in this timeframe, if obtained using the targeted searches in the most relevant databases. The review team should be larger, and standardized procedures for reviewing of the results and data extraction should be applied. In contrast to previous timeframe, merit review process may be feasible. For both timeframes, brief consultations with small transdisciplinary team should be conducted at the beginning and in the final stage of the review to discuss important matters.

For RLRs spanning several months, more comprehensive methodology may be adapted in terms of data synthesis and types of evidence. However, authors advise that review may be best conducted with a small review team in order to allow for more in-depth interpretation and iteration.

Studies analyzing methodology

There have been two interesting publications summarizing the results of Delphi consensus on the RLR methodology identified and included in this review [ 12 , 13 ].

Tricco et al. [ 13 ] first conducted an international survey and scoping review to collect information on the possible approaches to the running of rapid reviews, based on which, they employed a modified Delphi method that included inputs from 113 stakeholders to explore the most optimized approach. Among the six most frequent rapid review approaches (not all detailed here) being evaluated, the approach that combines inclusion of published literature only, a search of more than one database and limitations by date and language, study selection by one analyst, data extraction, and quality assessment by one analyst and one verifier, was perceived as the most feasible approach (72%, 81/113 responses) with the potentially lowest risk of bias (12%, 12/103). The approach ranked as the first one when considering timelines assumes updating of the search from a previously published review, no additional limits on search, studies selection and data extraction done by one reviewer, and no quality assessment. Finally, based on the publication, the most comprehensive RLRs can be made by moving on with the following rules: searching more than one database and grey literature and using date restriction, and assigning one reviewer working on screening, data extraction, and risk of bias assessment ( Table 1 ). Pandor et al. [ 12 ] introduced a decision tool for SelecTing Approaches for Rapid Reviews (STARR) that were produced through the Delphi consensus of international experts through an iterative and rigorous process. Participants were asked to assess the importance of predefined items in four domains related to the rapid review process: interaction with commissioners, understanding the evidence base, data extraction and synthesis methods, and reporting of rapid review methods. All items assigned to four domains achieved > 70% of consensus, and in that way, the first consensus-driven tool has been created that supports authors of RLRs in planning and deciding on approaches.

Six most frequent approaches to RLRs (adapted from Tricco et al. [ 13 ]).

Haby et al. [ 14 ] run searches of 11 databases and two websites and developed a comprehensive overview of the methodology of RLRs. With five SLRs and one RCT being finally included, they identified the following approaches used in RLRs to make them faster than full SLRs: limiting the number and scope of questions, searching fewer databases, limited searching of grey literature, restrictions on language and date (e.g., English only, most recent publications), updating the existing SLRs, eliminating or limiting hand searches of reference lists, noniterative search strategies, eliminating consultation with experts, limiting dual study selection, data extraction and quality assessment, minimal data synthesis with short concise conclusions or recommendations. All the SLRs included in this review were consistent in stating that no agreed definition of rapid reviews is available, and there is still no final agreement on the best methodological rules to be followed.

Gordon et al. [ 4 ] explained the advantages of performing a focused review and provided 12 tips for its conduction. They define focused reviews as ‘a form of knowledge synthesis in which the components of the systematic process are applied to facilitate the analysis of a focused research question’. The first tip presented by the authors is related to deciding if a focused review is a right solution for the considered project. RLRs will suit emerging topics, approaches, or assessments where early synthesis can support doctors, policymakers, etc., but also can direct future research. The second, third, and fourth tips highlight the importance of running preliminary searches and considering narrowing the results by using reasonable constraints taking into account the local context, problems, efficiency perspectives, and available time. Further tips include creating a team of experienced reviewers working on the RLRs, thinking about the target journal from the beginning of work on the rapid review, registering the search protocol on the PROSPERO registry, and the need for contacting authors of papers when data available in publications are missing or incongruent. The last three tips are related to the choice of evidence synthesis method, using the visual presentation of data, and considering and describing all the limitations of the focused review.

Finally, a new publication by Tricco et al. from 2022, describing JBI position statement [ 15 ] underlined that for the time being, there is no specific tool for critical appraisal of the RLR’s methodological quality. Instead, reviewers may use available tools to assess the risk of bias or quality of SLRs, like ROBIS, the JBI critical appraisal tools, or the assessment of multiple systematic reviews (AMSTAR).

Inconsistency in the definitions and methodologies of RLR

Although RLR was broadly perceived as an approach to quicken the conduct of conventional SLR, there is a lack of consensus on the formal definition of the RLR, so as to the best approaches to perform it. Only in 2021, a study proposing unified definition was published; however, it is important to note that the most accurate definition was only matching slightly over 50% of papers analysed by the authors, which underlines the lack of homogeneity in the field [ 11 ]. The evidence-based supporting methods are evolving, and more evidence is needed to define the most robust approaches [ 5 ].

Diverse terms are used to describe the RLR, including ‘rapid review’, focused systematic review’, ‘quick scoping reviews’, and ‘rapid evidence assessments’. Although the general principles of conducting RLR are to accelerate the whole process, complexity was seen in the methodologies used for RLRs, as reflected in this study. Also, inconsistencies related to the scope of the questions, search strategies, inclusion criteria, study screening, full-text review, quality assessment, and evidence presentation were implied. All these factors may hamper decision-making about optimal methodologies for conducting rapid reviews, and as a result, the efficiency of RLR might be decreased. Additionally, researchers may tend to report the methodology of their reviews without a sufficient level of detail, making it difficult to appraise the quality and robustness of their work.

Advantages and weaknesses of RLR

Although RLR used simplified approaches for evidence synthesis compared with SLR, the methodologies for RLR should be replicable, rigorous, and transparent to the greatest extent [ 16 ]. When time and resources are limited, RLR could be a practical and efficient tool to provide the summary of evidence that is critical for making rapid clinical or policy-related decisions [ 5 ]. Focusing on specific questions that are of controversy or special interest could be powerful in reaffirming whether the existing recommendation statements are still appropriate [ 17 ].

The weakness of RLR should also be borne in mind, and the trade-off of using RLR should be carefully considered regarding the thoroughness of the search, breadth of a research question, and depth of analysis [ 18 ]. If allowed, SLR is preferred over RLR considering that some relevant studies might be omitted with narrowed search strategies and simplified screening process [ 14 ]. Additionally, omitting the quality assessment of included studies could result in an increased risk of bias, making the comprehensiveness of RLR compromised [ 13 ]. Furthermore, in situations that require high accuracy, for example, where a small relative difference in an intervention has great impacts, for the purpose of drafting clinical guidelines, or making licensing decisions, a comprehensive SLR may remain the priority [ 19 ]. Therefore, clear communications with policymakers are recommended to reach an agreement on whether an RLR is justified and whether the methodologies of RLR are acceptable to address the unanswered questions [ 18 ].

Disclosure statement

No potential conflict of interest was reported by the author(s).

• Systematic Review
• Open access
• Published: 23 May 2024

Systematic literature review of real-world evidence for treatments in HR+/HER2- second-line LABC/mBC after first-line treatment with CDK4/6i

• Veronique Lambert   ORCID: orcid.org/0000-0002-6984-0038 1 ,
• Sarah Kane   ORCID: orcid.org/0009-0006-9341-4836 2   na1 ,
• Belal Howidi   ORCID: orcid.org/0000-0002-1166-7631 2   na1 ,
• Bao-Ngoc Nguyen   ORCID: orcid.org/0000-0001-6026-2270 2   na1 ,
• David Chandiwana   ORCID: orcid.org/0009-0002-3499-2565 3 ,
• Yan Wu   ORCID: orcid.org/0009-0008-3348-9232 1 ,
• Michelle Edwards   ORCID: orcid.org/0009-0001-4292-3140 3 &
• Imtiaz A. Samjoo   ORCID: orcid.org/0000-0003-1415-8055 2   na1  

BMC Cancer volume  24 , Article number:  631 ( 2024 ) Cite this article

Metrics details

Cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i) combined with endocrine therapy (ET) are currently recommended by the National Comprehensive Cancer Network (NCCN) guidelines and the European Society for Medical Oncology (ESMO) guidelines as the first-line (1 L) treatment for patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative, locally advanced/metastatic breast cancer (HR+/HER2- LABC/mBC). Although there are many treatment options, there is no clear standard of care for patients following 1 L CDK4/6i. Understanding the real-world effectiveness of subsequent therapies may help to identify an unmet need in this patient population. This systematic literature review qualitatively synthesized effectiveness and safety outcomes for treatments received in the real-world setting after 1 L CDK4/6i therapy in patients with HR+/ HER2- LABC/mBC.

MEDLINE®, Embase, and Cochrane were searched using the Ovid® platform for real-world evidence studies published between 2015 and 2022. Grey literature was searched to identify relevant conference abstracts published from 2019 to 2022. The review was conducted in accordance with PRISMA guidelines (PROSPERO registration: CRD42023383914). Data were qualitatively synthesized and weighted average median real-world progression-free survival (rwPFS) was calculated for NCCN/ESMO-recommended post-1 L CDK4/6i treatment regimens.

Twenty records (9 full-text articles and 11 conference abstracts) encompassing 18 unique studies met the eligibility criteria and reported outcomes for second-line (2 L) treatments after 1 L CDK4/6i; no studies reported disaggregated outcomes in the third-line setting or beyond. Sixteen studies included NCCN/ESMO guideline-recommended treatments with the majority evaluating endocrine-based therapy; five studies on single-agent ET, six studies on mammalian target of rapamycin inhibitors (mTORi) ± ET, and three studies with a mix of ET and/or mTORi. Chemotherapy outcomes were reported in 11 studies. The most assessed outcome was median rwPFS; the weighted average median rwPFS was calculated as 3.9 months (3.3-6.0 months) for single-agent ET, 3.6 months (2.5–4.9 months) for mTORi ± ET, 3.7 months for a mix of ET and/or mTORi (3.0–4.0 months), and 6.1 months (3.7–9.7 months) for chemotherapy. Very few studies reported other effectiveness outcomes and only two studies reported safety outcomes. Most studies had heterogeneity in patient- and disease-related characteristics.

Conclusions

The real-world effectiveness of current 2 L treatments post-1 L CDK4/6i are suboptimal, highlighting an unmet need for this patient population.

Peer Review reports

Introduction

Breast cancer (BC) is the most diagnosed form of cancer in women with an estimated 2.3 million new cases diagnosed worldwide each year [ 1 ]. BC is the second leading cause of cancer death, accounting for 685,000 deaths worldwide per year [ 2 ]. By 2040, the global burden associated with BC is expected to surpass three million new cases and one million deaths annually (due to population growth and aging) [ 3 ]. Numerous factors contribute to global disparities in BC-related mortality rates, including delayed diagnosis, resulting in a high number of BC cases that have progressed to locally advanced BC (LABC) or metastatic BC (mBC) [ 4 , 5 , 6 ]. In the United States (US), the five-year survival rate for patients who progress to mBC is three times lower (31%) than the overall five-year survival rate for all stages (91%) [ 6 , 7 ].

Hormone receptor (HR) positive (i.e., estrogen receptor and/or progesterone receptor positive) coupled with negative human epidermal growth factor 2 (HER2) expression is the most common subtype of BC, accounting for ∼ 60–70% of all BC cases [ 8 , 9 ]. Historically, endocrine therapy (ET) through estrogen receptor modulation and/or estrogen deprivation has been the standard of care for first-line (1 L) treatment of HR-positive/HER2-negative (HR+/HER2-) mBC [ 10 ]. However, with the approval of the cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) palbociclib in combination with the aromatase inhibitor (AI) letrozole in 2015 by the US Food and Drug Administration (FDA), 1 L treatment practice patterns have evolved such that CDK4/6i (either in combination with AIs or with fulvestrant) are currently considered the standard of care [ 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. Other CDK4/6i (ribociclib and abemaciclib) in combination with ET are approved for the treatment of HR+/HER2- LABC/mBC; 1 L use of ribociclib in combination with an AI was granted FDA approval in March 2017 for postmenopausal women (with expanded approval in July 2018 for pre/perimenopausal women and for use in 1 L with fulvestrant for patients with disease progression on ET as well as for postmenopausal women), and abemaciclib in combination with fulvestrant was granted FDA approval in September 2017 for patients with disease progression following ET and as monotherapy in cases where disease progression occurs following ET and prior chemotherapy in mBC (with expanded approval in February 2018 for use in 1 L in combination with an AI for postmenopausal women) [ 18 , 19 , 20 , 21 ].

Clinical trials investigating the addition of CDK4/6i to ET have demonstrated significant improvement in progression-free survival (PFS) and significant (ribociclib) or numerical (palbociclib and abemaciclib) improvement in overall survival (OS) compared to ET alone in patients with HR+/HER2- advanced or mBC, making this combination treatment the recommended option in the 1 L setting [ 22 , 23 , 24 , 25 , 26 , 27 ]. However, disease progression occurs in a significant portion of patients after 1 L CDK4/6i treatment [ 28 ] and the optimal treatment sequence after progression on CDK4/6i remains unclear [ 29 ]. At the time of this review (literature search conducted December 14, 2022), guidelines by the National Comprehensive Cancer Network (NCCN) and the European Society for Medical Oncology (ESMO) recommend various options for the treatment of HR+/HER2- advanced BC in the second-line (2 L) setting, including fulvestrant monotherapy, mammalian target of rapamycin inhibitors (mTORi; e.g., everolimus) ± ET, alpelisib + fulvestrant (if phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha mutation positive [PIK3CA-m+]), poly-ADP ribose polymerase inhibitors (PARPi) including olaparib or talazoparib (if breast cancer gene/partner and localizer of BRCA2 positive [BRCA/PALB2m+]), and chemotherapy (in cases when a visceral crisis is present) [ 15 , 16 ]. CDK4/6i can also be used in 2 L [ 16 , 30 ]; however, limited data are available to support CDK4/6i rechallenge after its use in the 1 L setting [ 15 ]. Depending on treatments used in the 1 L and 2 L settings, treatment in the third-line setting is individualized based on the patient’s response to prior treatments, tumor load, duration of response, and patient preference [ 9 , 15 ]. Understanding subsequent treatments after 1 L CDK4/6i, and their associated effectiveness, is an important focus in BC research.

Treatment options for HR+/HER2- LABC/mBC continue to evolve, with ongoing research in both clinical trials and in the real-world setting. Real-world evidence (RWE) offers important insights into novel therapeutic regimens and the effectiveness of treatments for HR+/HER2- LABC/mBC. The effectiveness of the current treatment options following 1 L CDK4/6i therapy in the real-world setting highlights the unmet need in this patient population and may help to drive further research and drug development. In this study, we conducted a systematic literature review (SLR) to qualitatively summarize the effectiveness and safety of treatment regimens in the real-world setting after 1 L treatment with CDK4/6i in patients with HR+/HER2- LABC/mBC.

Literature search

An SLR was performed in accordance with the Cochrane Handbook for Systematic Reviews of Interventions [ 31 ] and reported in alignment with the Preferred Reporting Items for Systematic Literature Reviews and Meta-Analyses (PRISMA) statement [ 32 ] to identify all RWE studies assessing the effectiveness and safety of treatments used for patients with HR+/HER2- LABC/mBC following 1 L CDK4/6i therapy and received subsequent treatment in 2 L and beyond (2 L+). The Ovid® platform was used to search MEDLINE® (including Epub Ahead of Print and In-Process, In-Data-Review & Other Non-Indexed Citations), Ovid MEDLINE® Daily, Embase, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews by an experienced medical information specialist. The MEDLINE® search strategy was peer-reviewed independently by a senior medical information specialist before execution using the Peer Review of Electronic Search Strategies (PRESS) checklist [ 33 ]. Searches were conducted on December 14, 2022. The review protocol was developed a priori and registered with the International Prospective Register of Systematic Review (PROSPERO; CRD42023383914) which outlined the population, intervention, comparator, outcome, and study design (PICOS) criteria and methodology used to conduct the review (Table  1 ).

Search strategies utilized a combination of controlled vocabulary (e.g., “HER2 Breast Cancer” or “HR Breast Cancer”) and keywords (e.g., “Retrospective studies”). Vocabulary and syntax were adjusted across databases. Published and validated filters were used to select for study design and were supplemented using additional medical subject headings (MeSH) terms and keywords to select for RWE and nonrandomized studies [ 34 ]. No language restrictions were included in the search strategy. Animal-only and opinion pieces were removed from the results. The search was limited to studies published between January 2015 and December 2022 to reflect the time at which FDA approval was granted for the first CDK4/6i agent (palbociclib) in combination with AI for the treatment of LABC/mBC [ 35 ]. Further search details are presented in Supplementary Material 1 .

Grey literature sources were also searched to identify relevant abstracts and posters published from January 2019 to December 2022 for prespecified relevant conferences including ESMO, San Antonio Breast Cancer Symposium (SABCS), American Society of Clinical Oncology (ASCO), the International Society for Pharmacoeconomics and Outcomes Research (ISPOR US), and the American Association for Cancer Research (AACR). A search of ClinicalTrials.gov was conducted to validate the findings from the database and grey literature searches.

Study selection, data extraction & weighted average calculation

Studies were screened for inclusion using DistillerSR Version 2.35 and 2.41 (DistillerSR Inc. 2021, Ottawa, Canada) by two independent reviewers based on the prespecified PICOS criteria (Table  1 ). A third reviewer was consulted to resolve any discrepancies during the screening process. Studies were included if they reported RWE on patients aged ≥ 18 years with HR+/HER2- LABC/mBC who received 1 L CDK4/6i treatment and received subsequent treatment in 2 L+. Studies were excluded if they reported the results of clinical trials (i.e., non-RWE), were published in any language other than English, and/or were published prior to 2015 (or prior to 2019 for conference abstracts and posters). For studies that met the eligibility criteria, data relating to study design and methodology, details of interventions, patient eligibility criteria and baseline characteristics, and outcome measures such as efficacy, safety, tolerability, and patient-reported outcomes (PROs), were extracted (as available) using a Microsoft Excel®-based data extraction form (Microsoft Corporation, WA, USA). Data extraction was performed by a single reviewer and was confirmed by a second reviewer. Multiple publications identified for the same RWE study, patient population, and setting that reported data for the same intervention were linked and extracted as a single publication. Weighted average median real-world progression-free survival (rwPFS) values were calculated by considering the contribution to the median rwPFS of each study proportional to its respective sample size. These weighted values were then used to compute the overall median rwPFS estimate.

Quality assessment

The Newcastle-Ottawa scale (NOS) for nonrandomized (cohort) studies was used to assess the risk of bias for published, full-text studies [ 36 ]. The NOS allocates a maximum of nine points for the least risk of bias across three domains: (1) Formation of study groups (four points), (2) Comparability between study groups (two points), (3) Outcome ascertainment (three points). NOS scores can be categorized in three groups: very high risk of bias (0 to 3 points), high risk of bias (4 to 6), and low risk of bias (7 to 9) [ 37 ]. Risk of bias assessment was performed by one reviewer and validated by a second independent reviewer to verify accuracy. Due to limited methodological data by which to assess study quality, risk of bias assessment was not performed on conference abstracts or posters. An amendment to the PROSPERO record (CRD42023383914) for this study was submitted in relation to the quality assessment method (specifying usage of the NOS).

The database search identified 3,377 records; after removal of duplicates, 2,759 were screened at the title and abstract stage of which 2,553 were excluded. Out of the 206 reports retrieved and assessed for eligibility, an additional 187 records were excluded after full-text review; most of these studies were excluded for having patients with mixed lines of CDK4/6i treatment (i.e., did not receive CDK4/6i exclusively in 1 L) (Fig.  1 and Table S1 ). The grey literature search identified 753 records which were assessed for eligibility; of which 752 were excluded mainly due to the population not meeting the eligibility criteria (Fig.  1 ). In total, the literature searches identified 20 records (9 published full-text articles and 11 conference abstracts/posters) representing 18 unique RWE studies that met the inclusion criteria. The NOS quality scores for the included full-text articles are provided in Table S2 . The scores ranged from four to six points (out of a total score of nine) and the median score was five, indicating that all the studies suffered from a high risk of bias [ 37 ].

Most studies were retrospective analyses of chart reviews or medical registries, and all studies were published between 2017 and 2022 (Table S3 ). Nearly half of the RWE studies (8 out of 18 studies) were conducted in the US [ 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 ], while the remaining studies included sites in Canada, China, Germany, Italy, Japan, and the United Kingdom [ 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 ]. Sample sizes ranged from as few as 4 to as many as 839 patients across included studies, with patient age ranging from 26 to 86 years old.

Although treatment characteristics in the 1 L setting were not the focus of the present review, these details are captured in Table S3 . Briefly, several RWE studies reported 1 L CDK4/6i use in combination with ET (8 out of 18 studies) or as monotherapy (2 out of 18 studies) (Table S3 ). Treatments used in combination with 1 L CDK4/6i included letrozole, fulvestrant, exemestane, and anastrozole. Where reported (4 out of 18 studies), palbociclib was the most common 1 L CDK4/6i treatment. Many studies (8 out of 18 studies) did not report which specific CDK4/6i treatment(s) were used in 1 L or if its administration was in combination or monotherapy.

Characteristics of treatments after 1 L CDK4/6i therapy

Across all studies included in this review, effectiveness and safety data were only available for treatments administered in the 2 L setting after 1 L CDK4/6i treatment. No studies were identified that reported outcomes for patients treated in the third-line setting or beyond after 1 L CDK4/6i treatment. All 18 studies reported effectiveness outcomes in 2 L, with only two of these studies also describing 2 L safety outcomes. The distribution of outcomes reported in these studies is provided in Table S4 . Studies varied in their reporting of outcomes for 2 L treatments; some studies reported outcomes for a group of 2 L treatments while others described independent outcomes for specific 2 L treatments (i.e., everolimus, fulvestrant, or chemotherapy agents such as eribulin mesylate) [ 42 , 45 , 50 , 54 , 55 ]. Due to the heterogeneity in treatment classes reported in these studies, this data was categorized (as described below) to align with the guidelines provided by NCCN and ESMO [ 15 , 16 ]. The treatment class categorizations for the purpose of this review are: single-agent ET (patients who exclusively received a single-agent ET after 1 L CDK4/6i treatment), mTORi ± ET (patients who exclusively received an mTORi with or without ET after 1 L CDK4/6i treatment), mix of ET and/or mTORi (patients who may have received only ET, only mTORi, and/or both treatments but the studies in this group lacked sufficient information to categorize these patients in the “single-agent ET” or “mTOR ± ET” categories), and chemotherapy (patients who exclusively received chemotherapy after 1 L CDK4/6i treatment). Despite ESMO and NCCN guidelines indicating that limited evidence exists to support rechallenge with CDK4/6i after 1 L CDK4/6i treatment [ 15 , 16 ], two studies reported outcomes for this treatment approach. Data for such patients were categorized as “ CDK4/6i ± ET ” as it was unclear how many patients receiving CDK4/6i rechallenge received concurrent ET. All other patient groups that lacked sufficient information or did not report outcome/safety data independently (i.e., grouped patients with mixed treatments) to categorize as one of the treatment classes described above were grouped as “ other ”.

The majority of studies reported effectiveness outcomes for endocrine-based therapy after 1 L CDK4/6i treatment; five studies for single-agent ET, six studies for mTORi ± ET, and three studies for a mix of ET and/or mTORi (Fig.  2 ). Eleven studies reported effectiveness outcomes for chemotherapy after 1 L CDK4/6i treatment, and only two studies reported effectiveness outcomes for CDK4/6i rechallenge ± ET. Eight studies that described effectiveness outcomes were grouped into the “other” category. Safety data was only reported in two studies: one study evaluating the chemotherapy agent eribulin mesylate and one evaluating the mTORi everolimus.

Effectiveness outcomes

Real-world progression-free survival

Median rwPFS was described in 13 studies (Tables  2 and Table S5 ). Across the 13 studies, the median rwPFS ranged from 2.5 months [ 49 ] to 17.3 months [ 39 ]. Out of the 13 studies reporting median rwPFS, 10 studies reported median rwPFS for a 2 L treatment recommended by ESMO and NCCN guidelines, which ranged from 2.5 months [ 49 ] to 9.7 months [ 45 ].

Weighted average median rwPFS was calculated for 2 L treatments recommended by both ESMO and NCCN guidelines (Fig.  3 ). The weighted average median rwPFS for single-agent ET was 3.9 months ( n  = 92 total patients) and was derived using data from two studies reporting median rwPFS values of 3.3 months ( n  = 70) [ 38 ] and 6.0 months ( n  = 22) [ 40 ]. For one study ( n  = 7) that reported outcomes for single agent ET, median rwPFS was not reached during the follow-up period; as such, this study was excluded from the weighted average median rwPFS calculation [ 49 ].

The weighted average median rwPFS for mTORi ± ET was 3.6 months ( n  = 128 total patients) and was derived based on data from 3 studies with median rwPFS ranging from 2.5 months ( n  = 4) [ 49 ] to 4.9 months ( n  = 25) [ 54 ] (Fig.  3 ). For patients who received a mix of ET and/or mTORi but could not be classified into the single-agent ET or mTORi ± ET treatment classes, the weighted average median rwPFS was calculated to be 3.7 months ( n  = 17 total patients). This was calculated based on data from two studies reporting median rwPFS values of 3.0 months ( n  = 5) [ 46 ] and 4.0 months ( n  = 12) [ 49 ]. Notably, one study of patients receiving ET and/or everolimus reported a median rwPFS duration of 3.0 months; however, this study was excluded from the weighted average median rwPFS calculation for the ET and/or mTORi class as the sample size was not reported [ 53 ].

The weighted average median rwPFS for chemotherapy was 6.1 months ( n  = 499 total patients), calculated using data from 7 studies reporting median rwPFS values ranging from 3.7 months ( n  = 249) [ 38 ] to 9.7 months ( n  = 121) [ 45 ] (Fig.  3 ). One study with a median rwPFS duration of 5.6 months was not included in the weighted average median rwPFS calculation as the study did not report the sample size [ 53 ]. A second study was excluded from the calculation since the reported median rwPFS was not reached during the study period ( n  = 7) [ 41 ].

Although 2 L CDK4/6i ± ET rechallenge lacks sufficient information to support recommendation by ESMO and NCCN guidelines, the limited data currently available for this treatment have shown promising results. Briefly, two studies reported median rwPFS for CDK4/6i ± ET with values of 8.3 months ( n  = 302) [ 38 ] and 17.3 months ( n  = 165) (Table  2 ) [ 39 ]. The remaining median rwPFS studies reported data for patients classified as “Other” (Table S5 ). The “Other” category included median rwPFS outcomes from seven studies, and included a myriad of treatments (e.g., ET, mTOR + ET, chemotherapy, CDK4/6i + ET, alpelisib + fulvestrant, chidamide + ET) for which disaggregated median rwPFS values were not reported.

Overall survival

Median OS for 2 L treatment was reported in only three studies (Table  2 ) [ 38 , 42 , 43 ]. Across the three studies, the 2 L median OS ranged from 5.2 months ( n  = 3) [ 43 ] to 35.7 months ( n  = 302) [ 38 ]. Due to the lack of OS data in most of the studies, weighted averages could not be calculated. No median OS data was reported for the single-agent ET treatment class whereas two studies reported median OS for the mTORi ± ET treatment class, ranging from 5.2 months ( n  = 3) [ 43 ] to 21.8 months ( n  = 54) [ 42 ]. One study reported 2 L median OS of 24.8 months for a single patient treated with chemotherapy [ 43 ]. The median OS data in the CDK4/6i ± ET rechallenge group was 35.7 months ( n  = 302) [ 38 ].

Patient mortality was reported in three studies [ 43 , 44 , 45 ]. No studies reported mortality for the single-agent ET treatment class and only one study reported this outcome for the mTORi ± ET treatment class, where 100% of patients died ( n  = 3) as a result of rapid disease progression [ 43 ]. For the chemotherapy class, one study reported mortality for one patient receiving 2 L capecitabine [ 43 ]. An additional study reported eight deaths (21.7%) following 1 L CDK4/6i treatment; however, this study did not disclose the 2 L treatments administered to these patients [ 44 ].

Other clinical endpoints

The studies included limited information on additional clinical endpoints; two studies reported on time-to-discontinuation (TTD), two reported on duration of response (DOR), and one each on time-to-next-treatment (TTNT), time-to-progression (TTP), objective response rate (ORR), clinical benefit rate (CBR), and stable disease (Tables  2 and Table S5 ).

Safety, tolerability, and patient-reported outcomes

Safety and tolerability data were reported in two studies [ 40 , 45 ]. One study investigating 2 L administration of the chemotherapy agent eribulin mesylate reported 27 patients (22.3%) with neutropenia, 3 patients (2.5%) with febrile neutropenia, 10 patients (8.3%) with peripheral neuropathy, and 14 patients (11.6%) with diarrhea [ 45 ]. Of these, neutropenia of grade 3–4 severity occurred in 9 patients (33.3%) [ 45 ]. A total of 55 patients (45.5%) discontinued eribulin mesylate treatment; 1 patient (0.83%) discontinued treatment due to adverse events [ 45 ]. Another study reported that 5 out of the 22 patients receiving the mTORi everolimus combined with ET in 2 L (22.7%) discontinued treatment due to toxicity [ 40 ]. PROs were not reported in any of the studies included in the SLR.

The objective of this study was to summarize the existing RWE on the effectiveness and safety of therapies for patients with HR+/HER2- LABC/mBC after 1 L CDK4/6i treatment. We identified 18 unique studies reporting specifically on 2 L treatment regimens after 1 L CDK4/6i treatment. The weighted average median rwPFS for NCCN- and ESMO- guideline recommended 2 L treatments ranged from 3.6 to 3.9 months for ET-based treatments and was 6.1 months when including chemotherapy-based regimens. Treatment selection following 1 L CDK4/6i therapy remains challenging primarily due to the suboptimal effectiveness or significant toxicities (e.g., chemotherapy) associated with currently available options [ 56 ]. These results highlight that currently available 2 L treatments for patients with HR+/HER2- LABC/mBC who have received 1 L CDK4/6i are suboptimal, as evidenced by the brief median rwPFS duration associated with ET-based treatments, or notable side effects and toxicity linked to chemotherapy. This conclusion is aligned with a recent review highlighting the limited effectiveness of treatment options for HR+/HER2- LABC/mBC patients post-CDK4/6i treatment [ 56 , 57 ]. Registrational trials which have also shed light on the short median PFS of 2–3 months achieved by ET (i.e., fulvestrant) after 1 L CDK4/6i therapy emphasize the need to develop improved treatment strategies aimed at prolonging the duration of effective ET-based treatment [ 56 ].

The results of this review reveal a paucity of additional real-world effectiveness and safety evidence after 1 L CDK4/6i treatment in HR+/HER2- LABC/mBC. OS and DOR were only reported in two studies while other clinical endpoints (i.e., TTD, TTNT, TTP, ORR, CBR, and stable disease) were only reported in one study each. Similarly, safety and tolerability data were only reported in two studies each, and PROs were not reported in any study. This hindered our ability to provide a comprehensive assessment of real-world treatment effectiveness and safety following 1 L CDK4/6i treatment. The limited evidence may be due to the relatively short period of time that has elapsed since CDK4/6i first received US FDA approval for 1 L treatment of HR+/HER2- LABC/mBC (2015) [ 35 ]. As such, almost half of our evidence was informed by conference abstracts. Similarly, no real-world studies were identified in our review that reported outcomes for treatments in the third- or later-lines of therapy after 1 L CDK4/6i treatment. The lack of data in this patient population highlights a significant gap which limits our understanding of the effectiveness and safety for patients receiving later lines of therapy. As more patients receive CDK4/6i therapy in the 1 L setting, the number of patients requiring subsequent lines of therapy will continue to grow. Addressing this data gap over time will be critical to improve outcomes for patients with HR+/HER2- LABC/mBC following 1 L CDK4/6i therapy.

There are several strengths of this study, including adherence to the guidelines outlined in the Cochrane Handbook to ensure a standardized and reliable approach to the SLR [ 58 ] and reporting of the SLR following PRISMA guidelines to ensure transparency and reproducibility [ 59 ]. Furthermore, the inclusion of only RWE studies allowed us to assess the effectiveness of current standard of care treatments outside of a controlled environment and enabled us to identify an unmet need in this patient population.

This study had some notable limitations, including the lack of safety and additional effectiveness outcomes reported. In addition, the dearth of studies reporting PROs is a limitation, as PROs provide valuable insight into the patient experience and are an important aspect of assessing the impact of 2 L treatments on patients’ quality of life. The studies included in this review also lacked consistent reporting of clinical characteristics (e.g., menopausal status, sites of metastasis, prior surgery) making it challenging to draw comprehensive conclusions or comparisons based on these factors across the studies. Taken together, there exists an important gap in our understanding of the long-term management of patients with HR+/HER2- LABC/mBC. Additionally, the effectiveness results reported in our evidence base were informed by small sample sizes; many of the included studies reported median rwPFS based on less than 30 patients [ 39 , 40 , 41 , 46 , 49 , 51 , 60 ], with two studies not reporting the sample size at all [ 47 , 53 ]. This may impact the generalizability and robustness of the results. Relatedly, the SLR database search was conducted in December 2022; as such, novel agents (e.g., elacestrant and capivasertib + fulvestrant) that have since received FDA approval for the treatment of HR+/HER2- LABC/mBC may impact current 2 L rwPFS outcomes [ 61 , 62 ]. Finally, relative to the number of peer-reviewed full-text articles, this SLR identified eight abstracts and one poster presentation, comprising half (50%) of the included unique studies. As conference abstracts are inherently limited by how much content that can be described due to word limit constraints, this likely had implications on the present synthesis whereby we identified a dearth of real-world effectiveness outcomes in patients with HR+/HER2- LABC/mBC treated with 1 L CDK4/6i therapy.

Future research in this area should aim to address the limitations of the current literature and provide a more comprehensive understanding of optimal sequencing of effective and safe treatment for patients following 1 L CDK4/6i therapy. Specifically, future studies should strive to report robust data related to effectiveness, safety, and PROs for patients receiving 2 L treatment after 1 L CDK4/6i therapy. Future studies should also aim to understand the mechanism underlying CDK4/6i resistance. Addressing these gaps in knowledge may improve the long-term real-world management of patients with HR+/HER2- LABC/mBC. A future update of this synthesis may serve to capture a wider breadth of full-text, peer-reviewed articles to gain a more robust understanding of the safety, effectiveness, and real-world treatment patterns for patients with HR+/HER2- LABC/mBC. This SLR underscores the necessity for ongoing investigation and the development of innovative therapeutic approaches to address these gaps and improve patient outcomes.

This SLR qualitatively summarized the existing real-world effectiveness data for patients with HR+/HER2- LABC/mBC after 1 L CDK4/6i treatment. Results of this study highlight the limited available data and the suboptimal effectiveness of treatments employed in the 2 L setting and underscore the unmet need in this patient population. Additional studies reporting effectiveness and safety outcomes, in addition to PROs, for this patient population are necessary and should be the focus of future research.

PRISMA flow diagram. *Two included conference abstracts reported the same information as already included full-text reports, hence both conference abstracts were not identified as unique. Abbreviations: 1 L = first-line; AACR = American Association of Cancer Research; ASCO = American Society of Clinical Oncology; CDK4/6i = cyclin-dependent kinase 4/6 inhibitor; ESMO = European Society for Medical Oncology; ISPOR = Professional Society for Health Economics and Outcomes Research; n = number of studies; NMA = network meta-analysis; pts = participants; SABCS = San Antonio Breast Cancer Symposium; SLR = systematic literature review.

Number of studies reporting effectiveness outcomes exclusively for each treatment class. *Studies that lack sufficient information on effectiveness outcomes to classify based on the treatment classes outlined in the legend above. Abbreviations: CDK4/6i = cyclin-dependent kinase 4/6 inhibitor; ET = endocrine therapy; mTORi = mammalian target of rapamycin inhibitor.

Weighted average median rwPFS for 2 L treatments (recommended in ESMO/NCCN guidelines) after 1 L CDK4/6i treatment. Circular dot represents weighted average median across studies. Horizontal bars represent the range of values reported in these studies. Abbreviations: CDK4/6i = cyclin-dependent kinase 4/6 inhibitor; ESMO = European Society for Medical Oncology; ET = endocrine therapy, mTORi = mammalian target of rapamycin inhibitor; n = number of patients; NCCN = National Comprehensive Cancer Network; rwPFS = real-world progression-free survival.

Data availability

All data generated or analyzed during this study are included in this published article [and its supplementary information files]. This study is registered with PROSPERO (CRD42023383914).

Abbreviations

Second-line

Second-line treatment setting and beyond

American Association of Cancer Research

Aromatase inhibitor

American Society of Clinical Oncology

• Breast cancer

breast cancer gene/partner and localizer of BRCA2 positive

Clinical benefit rate

Cyclin-dependent kinase 4/6 inhibitor

Complete response

Duration of response

European Society for Medical Oncology

Food and Drug Administration

Human epidermal growth factor receptor 2

Human epidermal growth factor receptor 2 negative

Hormone receptor

Hormone receptor positive

Professional Society for Health Economics and Outcomes Research

Locally advanced breast cancer

Metastatic breast cancer

Medical Literature Analysis and Retrieval System Online

Medical subject headings

Mammalian target of rapamycin inhibitor

National Comprehensive Cancer Network

Newcastle Ottawa Scale

Objective response rate

Poly-ADP ribose polymerase inhibitor

Progression-free survival

Population, Intervention, Comparator, Outcome, Study Design

Partial response

Preferred Reporting Items for Systematic Literature Reviews and Meta-Analyses

Patient-reported outcomes

• Real-world evidence

San Antonio Breast Cancer Symposium

• Systematic literature review

Time-to-discontinuation

Time-to-next-treatment

Time-to-progression

United States

Łukasiewicz S, Czeczelewski M, Forma A, Baj J, Sitarz R, Stanisławek A, Breast, Cancer—Epidemiology. Risk factors, classification, prognostic markers, and current treatment Strategies—An. Updated Rev Cancers. 2021;13(17):4287.

Google Scholar  

World Health Organization (WHO). Breast Cancer Facts Sheet [updated July 12 2023. https://www.who.int/news-room/fact-sheets/detail/breast-cancer .

Arnold M, Morgan E, Rumgay H, Mafra A, Singh D, Laversanne M, et al. Current and future burden of breast cancer: global statistics for 2020 and 2040. Breast. 2022;66:15–23.

Article   PubMed   PubMed Central   Google Scholar  

Wilkinson L, Gathani T. Understanding breast cancer as a global health concern. Br J Radiol. 2022;95(1130):20211033.

Article   PubMed   Google Scholar  

Giaquinto AN, Sung H, Miller KD, Kramer JL, Newman LA, Minihan A et al. Breast Cancer Statistics, 2022. CA: A Cancer Journal for Clinicians. 2022;72(6):524– 41.

National Cancer Institute (NIH). Cancer Stat Facts: Female Breast Cancer [updated 2020. https://seer.cancer.gov/statfacts/html/breast.html .

American Cancer Society. Key Statistics for Breast Cancer [ https://www.cancer.org/cancer/types/breast-cancer/about/how-common-is-breast-cancer.html .

Zagami P, Carey LA. Triple negative breast cancer: pitfalls and progress. npj Breast Cancer. 2022;8(1):95.

Article   CAS   PubMed   PubMed Central   Google Scholar  

Matutino A, Joy AA, Brezden-Masley C, Chia S, Verma S. Hormone receptor-positive, HER2-negative metastatic breast cancer: redrawing the lines. Curr Oncol. 2018;25(Suppl 1):S131–41.

Lloyd MR, Wander SA, Hamilton E, Razavi P, Bardia A. Next-generation selective estrogen receptor degraders and other novel endocrine therapies for management of metastatic hormone receptor-positive breast cancer: current and emerging role. Ther Adv Med Oncol. 2022;14:17588359221113694.

Cardoso F, Senkus E, Costa A, Papadopoulos E, Aapro M, André F, et al. 4th ESO-ESMO International Consensus guidelines for advanced breast Cancer (ABC 4)†. Ann Oncol. 2018;29(8):1634–57.

Article   CAS   PubMed   Google Scholar  

US Food Drug Administration. Palbociclib (Ibrance) 2017 [updated March 31, 2017. https://www.fda.gov/drugs/resources-information-approved-drugs/palbociclib-ibrance .

US Food Drug Administration. FDA expands ribociclib indication in HR-positive, HER2-negative advanced or metastatic breast cancer 2018 [updated July 18. 2018. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-expands-ribociclib-indication-hr-positive-her2-negative-advanced-or-metastatic-breast-cancer .

US Food Drug Administration. FDA approves abemaciclib for HR positive, HER2-negative breast cancer 2017 [updated Sept 28. 2017. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-abemaciclib-hr-positive-her2-negative-breast-cancer .

NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®). Breast Cancer 2022 [ https://www.nccn.org/professionals/physician_gls/pdf/breast.pdf .

Gennari A, André F, Barrios CH, Cortés J, de Azambuja E, DeMichele A, et al. ESMO Clinical Practice Guideline for the diagnosis, staging and treatment of patients with metastatic breast cancer. Ann Oncol. 2021;32(12):1475–95.

Beaver JA, Amiri-Kordestani L, Charlab R, Chen W, Palmby T, Tilley A, et al. FDA approval: Palbociclib for the Treatment of Postmenopausal Patients with estrogen Receptor-Positive, HER2-Negative metastatic breast Cancer. Clin Cancer Res. 2015;21(21):4760–6.

US Food Drug Administration. Ribociclib (Kisqali) [ https://www.fda.gov/drugs/resources-information-approved-drugs/ribociclib-kisqali#:~:text=On%20March%2013%2C%202017%2C%20the,hormone%20receptor%20(HR)%2Dpositive%2C .

US Food Drug Administration. FDA approves new treatment for certain advanced or metastatic breast cancers [ https://www.fda.gov/news-events/press-announcements/fda-approves-new-treatment-certain-advanced-or-metastatic-breast-cancers .

US Food Drug Administration. FDA expands ribociclib indication in HR-positive, HER2-negative advanced or metastatic breast cancer. 2018 [ https://www.fda.gov/drugs/resources-information-approved-drugs/fda-expands-ribociclib-indication-hr-positive-her2-negative-advanced-or-metastatic-breast-cancer .

US Food Drug Administration. FDA approves abemaciclib as initial therapy for HR-positive, HER2-negative metastatic breast cancer [ https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-abemaciclib-initial-therapy-hr-positive-her2-negative-metastatic-breast-cancer .

Turner NC, Slamon DJ, Ro J, Bondarenko I, Im S-A, Masuda N, et al. Overall survival with Palbociclib and fulvestrant in advanced breast Cancer. N Engl J Med. 2018;379(20):1926–36.

Slamon DJ, Neven P, Chia S, Fasching PA, De Laurentiis M, Im SA, et al. Phase III randomized study of Ribociclib and Fulvestrant in hormone Receptor-Positive, human epidermal growth factor receptor 2-Negative advanced breast Cancer: MONALEESA-3. J Clin Oncol. 2018;36(24):2465–72.

Goetz MP, Toi M, Campone M, Sohn J, Paluch-Shimon S, Huober J, et al. MONARCH 3: Abemaciclib as initial therapy for advanced breast Cancer. J Clin Oncol. 2017;35(32):3638–46.

Gopalan PK, Villegas AG, Cao C, Pinder-Schenck M, Chiappori A, Hou W, et al. CDK4/6 inhibition stabilizes disease in patients with p16-null non-small cell lung cancer and is synergistic with mTOR inhibition. Oncotarget. 2018;9(100):37352–66.

Watt AC, Goel S. Cellular mechanisms underlying response and resistance to CDK4/6 inhibitors in the treatment of hormone receptor-positive breast cancer. Breast Cancer Res. 2022;24(1):17.

Goetz M. MONARCH 3: final overall survival results of abemaciclib plus a nonsteroidal aromatase inhibitor as first-line therapy for HR+, HER2- advanced breast cancer. SABCS; 2023.

Munzone E, Pagan E, Bagnardi V, Montagna E, Cancello G, Dellapasqua S, et al. Systematic review and meta-analysis of post-progression outcomes in ER+/HER2– metastatic breast cancer after CDK4/6 inhibitors within randomized clinical trials. ESMO Open. 2021;6(6):100332.

Gennari A, André F, Barrios CH, Cortés J, de Azambuja E, DeMichele A, et al. ESMO Clinical Practice Guideline for the diagnosis, staging and treatment of patients with metastatic breast cancer. Annals of Oncology. 2021;32(12):1475-95.

European Society for Medical Oncology (ESMO). ESMO ​Metastatic Breast Cancer Living Guideline: ER-positive HER2-negative​ Breast Cancer​ [updated May 2023. https://www.esmo.org/living-guidelines/esmo-metastatic-breast-cancer-living-guideline/er-positive-her2-negative-breast-cancer .

Higgins JPT, Thomas J, Chandler J, Cumpston M, Li T, Welch PM VA, editors. Cochrane Handbook for Systematic Reviews of Interventions version 6.2 (updated February 2021). www.training.cochrane.org/handbook : Cochrane; 2021.

Page MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. PLoS Med. 2021;18(3):e1003583.

McGowan J, Sampson M, Salzwedel DM, Cogo E, Foerster V, Lefebvre C. PRESS peer review of electronic search strategies: 2015 Guideline Statement. J Clin Epidemiol. 2016;75:40–6.

Fraser C, Murray A, Burr J. Identifying observational studies of surgical interventions in MEDLINE and EMBASE. BMC Med Res Methodol. 2006;6(1):41.

US Food Drug Administration. Palbociclib (Ibrance). Silver Spring, MD: US Food and Drug Administration; 2017.

Book   Google Scholar  

GA Wells BS, D O’Connell J, Peterson V, Welch M, Losos PT. The Newcastle-Ottawa Scale (NOS) for assessing the quality of nonrandomised studies in meta-analyses [ https://www.ohri.ca/programs/clinical_epidemiology/oxford.asp .

Lo CK-L, Mertz D, Loeb M. Newcastle-Ottawa Scale: comparing reviewers’ to authors’ assessments. BMC Med Res Methodol. 2014;14(1):45.

Martin JM, Handorf EA, Montero AJ, Goldstein LJ. Systemic therapies following progression on first-line CDK4/6-inhibitor treatment: analysis of real-world data. Oncologist. 2022;27(6):441–6.

Kalinsky KM, Kruse M, Smyth EN, Guimaraes CM, Gautam S, Nisbett AR et al. Abstract P1-18-37: Treatment patterns and outcomes associated with sequential and non-sequential use of CDK4 and 6i for HR+, HER2- MBC in the real world. Cancer Research. 2022;82(4_Supplement):P1-18-37-P1-18-37.

Choong GM, Liddell S, Ferre RAL, O’Sullivan CC, Ruddy KJ, Haddad TC, et al. Clinical management of metastatic hormone receptor-positive, HER2-negative breast cancer (MBC) after CDK 4/6 inhibitors: a retrospective single-institution study. Breast Cancer Res Treat. 2022;196(1):229–37.

Xi J, Oza A, Thomas S, Ademuyiwa F, Weilbaecher K, Suresh R, et al. Retrospective Analysis of Treatment Patterns and effectiveness of Palbociclib and subsequent regimens in metastatic breast Cancer. J Natl Compr Canc Netw. 2019;17(2):141–7.

Rozenblit M, Mun S, Soulos P, Adelson K, Pusztai L, Mougalian S. Patterns of treatment with everolimus exemestane in hormone receptor-positive HER2-negative metastatic breast cancer in the era of targeted therapy. Breast Cancer Res. 2021;23(1):14.

Bashour SI, Doostan I, Keyomarsi K, Valero V, Ueno NT, Brown PH, et al. Rapid breast Cancer Disease Progression following cyclin dependent kinase 4 and 6 inhibitor discontinuation. J Cancer. 2017;8(11):2004–9.

Giridhar KV, Choong GM, Leon-Ferre R, O’Sullivan CC, Ruddy K, Haddad T, et al. Abstract P6-18-09: clinical management of metastatic breast cancer (MBC) after CDK 4/6 inhibitors: a retrospective single-institution study. Cancer Res. 2019;79:P6–18.

Article   Google Scholar  

Mougalian SS, Feinberg BA, Wang E, Alexis K, Chatterjee D, Knoth RL, et al. Observational study of clinical outcomes of eribulin mesylate in metastatic breast cancer after cyclin-dependent kinase 4/6 inhibitor therapy. Future Oncol. 2019;15(34):3935–44.

Moscetti LML, Riggi L, Sperduti I, Piacentini FOC, Toss A, Barbieri E, Cortesi L, Canino FMA, Zoppoli G, Frassoldati A, Schirone A, Dominici MECF. SEQUENCE OF TREATMENTS AFTER CDK4/6 THERAPY IN ADVANCED BREAST CANCER (ABC), A GOIRC MULTICENTER RETRO/ PROSPECTIVE STUDY. PRELIMINARY RESULTS IN THE RETROSPECTIVE SERIES OF 116 PATIENTS. Tumori. 2022;108(4S):80.

Menichetti AZE, Giorgi CA, Bottosso M, Leporati R, Giarratano T, Barbieri C, Ligorio F, Mioranza E, Miglietta F, Lobefaro R, Faggioni G, Falci C, Vernaci G, Di Liso E, Girardi F, Griguolo G, Vernieri C, Guarneri V, Dieci MV. CDK 4/6 INHIBITORS FOR METASTATIC BREAST CANCER: A MULTICENTER REALWORLD STUDY. Tumori. 2022;108(4S):70.

Marschner NW, Harbeck N, Thill M, Stickeler E, Zaiss M, Nusch A, et al. 232P Second-line therapies of patients with early progression under CDK4/6-inhibitor in first-line– data from the registry platform OPAL. Annals of Oncology. 2022;33:S643-S4

Gousis C, Lowe KMH, Kapiris M. V. Angelis. Beyond First Line CDK4/6 Inhibitors (CDK4/6i) and Aromatase Inhibitors (AI) in Patients with Oestrogen Receptor Positive Metastatic Breast Cancer (ERD MBC): The Guy’s Cancer Centre Experience. Clinical Oncology2022. p. e178.

Endo Y, Yoshimura A, Sawaki M, Hattori M, Kotani H, Kataoka A, et al. Time to chemotherapy for patients with estrogen receptor-positive breast Cancer and cyclin-dependent kinase 4 and 6 inhibitor use. J Breast Cancer. 2022;25(4):296–306.

Li Y, Li W, Gong C, Zheng Y, Ouyang Q, Xie N, et al. A multicenter analysis of treatment patterns and clinical outcomes of subsequent therapies after progression on palbociclib in HR+/HER2- metastatic breast cancer. Ther Adv Med Oncol. 2021;13:17588359211022890.

Amaro CP, Batra A, Lupichuk S. First-line treatment with a cyclin-dependent kinase 4/6 inhibitor plus an aromatase inhibitor for metastatic breast Cancer in Alberta. Curr Oncol. 2021;28(3):2270–80.

Crocetti SPM, Tassone L, Marcantognini G, Bastianelli L, Della Mora A, Merloni F, Cantini L, Scortichini L, Agostinelli V, Ballatore Z, Savini A, Maccaroni E. Berardi R. What is the best therapeutic sequence for ER-Positive/HER2- Negative metastatic breast cancer in the era of CDK4/6 inhibitors? A single center experience. Tumori. 2020;106(2S).

Nichetti F, Marra A, Giorgi CA, Randon G, Scagnoli S, De Angelis C, et al. 337P Efficacy of everolimus plus exemestane in CDK 4/6 inhibitors-pretreated or naïve HR-positive/HER2-negative breast cancer patients: A secondary analysis of the EVERMET study. Annals of Oncology. 2020;31:S382

Luhn P, O’Hear C, Ton T, Sanglier T, Hsieh A, Oliveri D, et al. Abstract P4-13-08: time to treatment discontinuation of second-line fulvestrant monotherapy for HR+/HER2– metastatic breast cancer in the real-world setting. Cancer Res. 2019;79(4Supplement):P4–13.

Mittal A, Molto Valiente C, Tamimi F, Schlam I, Sammons S, Tolaney SM et al. Filling the gap after CDK4/6 inhibitors: Novel Endocrine and Biologic Treatment options for metastatic hormone receptor positive breast Cancer. Cancers (Basel). 2023;15(7).

Ashai N, Swain SM. Post-CDK 4/6 inhibitor therapy: current agents and novel targets. Cancers (Basel). 2023;15(6).

Higgins JPTTJ, Chandler J, Cumpston M, Li T, Page MJ, Welch VA, editors. Cochrane Handbook for Systematic Reviews of Interventions version 6.3 (updated February 2022). www.training.cochrane.org/handbook : Cochrane; 2022.

Page MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ. 2021;372:n71.

Serdar CC, Cihan M, Yücel D, Serdar MA. Sample size, power and effect size revisited: simplified and practical approaches in pre-clinical, clinical and laboratory studies. Biochem Med (Zagreb). 2021;31(1):010502.

US Food Drug Administration. FDA approves elacestrant for ER-positive, HER2-negative, ESR1-mutated advanced or metastatic breast cancer [updated January 27 2023. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-elacestrant-er-positive-her2-negative-esr1-mutated-advanced-or-metastatic-breast-cancer .

US Food Drug Administration. FDA approves capivasertib with fulvestrant for breast cancer [updated November 16 2023. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-capivasertib-fulvestrant-breast-cancer .

Download references

Acknowledgements

The authors would like to acknowledge Joanna Bielecki who developed, conducted, and documented the database searches.

This study was funded by Pfizer Inc. (New York, NY, USA) and Arvinas (New Haven, CT, USA).

Author information

Sarah Kane, Belal Howidi, Bao-Ngoc Nguyen and Imtiaz A. Samjoo contributed equally to this work.

Authors and Affiliations

Pfizer, 10017, New York, NY, USA

Veronique Lambert & Yan Wu

EVERSANA, Burlington, ON, Canada

Sarah Kane, Belal Howidi, Bao-Ngoc Nguyen & Imtiaz A. Samjoo

Arvinas, 06511, New Haven, CT, USA

David Chandiwana & Michelle Edwards

You can also search for this author in PubMed   Google Scholar

Contributions

VL, IAS, SK, BH, BN, DC, YW, and ME participated in the conception and design of the study. IAS, SK, BH and BN contributed to the literature review, data collection, analysis, and interpretation of the data. VL, IAS, SK, BH, BN, DC, YW, and ME contributed to the interpretation of the data and critically reviewed for the importance of intellectual content for the work. VL, IAS, SK, BH, BN, DC, YW, and ME were responsible for drafting or reviewing the manuscript and for providing final approval. VL, IAS, SK, BH, BN, DC, YW, and ME meet the International Committee of Medical Journal Editors (ICMJE) criteria for authorship for this article, take responsibility for the integrity of the work, and have given their approval for this version to be published.

Corresponding author

Correspondence to Imtiaz A. Samjoo .

Ethics declarations

Ethics approval and consent to participate.

Not applicable.

Consent for publication

Competing interests.

The authors of this manuscript declare that the research presented was funded by Pfizer Inc. and Arvinas. While the support from Pfizer Inc. and Arvinas was instrumental in facilitating this research, the authors affirm that their interpretation of the data and the content of this manuscript were conducted independently and without bias to maintain the transparency and integrity of the research. IAS, SK, BH, and BN are employees of EVERSANA, Canada, which was a paid consultant to Pfizer in connection with the development of this manuscript.

Additional information

Publisher’s note.

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Supplementary Material 1

Supplementary material 2, rights and permissions.

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ . The Creative Commons Public Domain Dedication waiver ( http://creativecommons.org/publicdomain/zero/1.0/ ) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and permissions

About this article

Cite this article.

Lambert, V., Kane, S., Howidi, B. et al. Systematic literature review of real-world evidence for treatments in HR+/HER2- second-line LABC/mBC after first-line treatment with CDK4/6i. BMC Cancer 24 , 631 (2024). https://doi.org/10.1186/s12885-024-12269-8

Download citation

Received : 26 January 2024

Accepted : 16 April 2024

Published : 23 May 2024

DOI : https://doi.org/10.1186/s12885-024-12269-8

Share this article

Anyone you share the following link with will be able to read this content:

Sorry, a shareable link is not currently available for this article.

Provided by the Springer Nature SharedIt content-sharing initiative

• First-line CDK4/6i

ISSN: 1471-2407

• Submission enquiries: [email protected]
• General enquiries: [email protected]

Review of Related Literature (RRL) in Quantitative Research

Ai generator.

1. Introduction: This review examines the effects of physical activity on academic performance, focusing on quantitative research over the past decade.

2. Theoretical Framework : Based on Cognitive Function Theory, this review explores how physical activity influences cognitive function and academic outcomes.

3. Review of Empirical Studies :

Academic Performance

• Overall Impact : Smith & Brown (2015) found a positive correlation between regular physical activity and GPA in 1,000 high school students.
• Standardized Tests : Johnson & Lee (2016) reported higher standardized test scores in 500 middle school students engaging in daily physical activity.

Cognitive Function

• Executive Functioning : Davis & Miller (2017) showed aerobic exercise enhanced executive function, improving academic performance in 300 elementary students.
• Memory and Concentration : Thompson & Green (2018) found better memory and concentration in 400 high school students participating in physical activity programs.

4. Methodological Review : Studies used surveys, longitudinal designs, and experiments. Surveys provided broad data but couldn’t infer causation. Longitudinal studies offered insights into long-term effects but were resource-intensive. Experiments showed causation but had limited external validity.

5. Synthesis and Critique: Physical activity positively impacts academic performance. However, methodological inconsistencies suggest the need for more standardized and controlled studies.

6. Conclusion: Research highlights physical activity’s benefits on academic performance but calls for more rigorous studies to confirm these findings.

7. References :

• Smith, J., & Brown, L. (2015). Physical Activity and GPA in High School Students . Journal of Educational Research, 58(3), 201-210.
• Johnson, R., & Lee, P. (2016). Daily Physical Activity and Test Scores . Journal of School Health, 86(4), 283-291.
• Davis, M., & Miller, A. (2017). Aerobic Exercise and Executive Functioning . Cognitive Development, 32(2), 162-170.
• Thompson, H., & Green, K. (2018). Physical Activity and Cognitive Function . Educational Psychology, 39(1), 45-55.

Text prompt

• Instructive
• Professional

10 Examples of Public speaking

20 Examples of Gas lighting