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What are Systematic Reviews? (3 minutes, 24 second YouTube Video)

Systematic Literature Reviews: Steps & Resources

example of a medical literature review

These steps for conducting a systematic literature review are listed below . 

Also see subpages for more information about:

  • The different types of literature reviews, including systematic reviews and other evidence synthesis methods
  • Tools & Tutorials

Literature Review & Systematic Review Steps

  • Develop a Focused Question
  • Scope the Literature  (Initial Search)
  • Refine & Expand the Search
  • Limit the Results
  • Download Citations
  • Abstract & Analyze
  • Create Flow Diagram
  • Synthesize & Report Results

1. Develop a Focused   Question 

Consider the PICO Format: Population/Problem, Intervention, Comparison, Outcome

Focus on defining the Population or Problem and Intervention (don't narrow by Comparison or Outcome just yet!)

"What are the effects of the Pilates method for patients with low back pain?"

Tools & Additional Resources:

  • PICO Question Help
  • Stillwell, Susan B., DNP, RN, CNE; Fineout-Overholt, Ellen, PhD, RN, FNAP, FAAN; Melnyk, Bernadette Mazurek, PhD, RN, CPNP/PMHNP, FNAP, FAAN; Williamson, Kathleen M., PhD, RN Evidence-Based Practice, Step by Step: Asking the Clinical Question, AJN The American Journal of Nursing : March 2010 - Volume 110 - Issue 3 - p 58-61 doi: 10.1097/01.NAJ.0000368959.11129.79

2. Scope the Literature

A "scoping search" investigates the breadth and/or depth of the initial question or may identify a gap in the literature. 

Eligible studies may be located by searching in:

  • Background sources (books, point-of-care tools)
  • Article databases
  • Trial registries
  • Grey literature
  • Cited references
  • Reference lists

When searching, if possible, translate terms to controlled vocabulary of the database. Use text word searching when necessary.

Use Boolean operators to connect search terms:

  • Combine separate concepts with AND  (resulting in a narrower search)
  • Connecting synonyms with OR  (resulting in an expanded search)

Search:  pilates AND ("low back pain"  OR  backache )

Video Tutorials - Translating PICO Questions into Search Queries

  • Translate Your PICO Into a Search in PubMed (YouTube, Carrie Price, 5:11) 
  • Translate Your PICO Into a Search in CINAHL (YouTube, Carrie Price, 4:56)

3. Refine & Expand Your Search

Expand your search strategy with synonymous search terms harvested from:

  • database thesauri
  • reference lists
  • relevant studies

Example: 

(pilates OR exercise movement techniques) AND ("low back pain" OR backache* OR sciatica OR lumbago OR spondylosis)

As you develop a final, reproducible strategy for each database, save your strategies in a:

  • a personal database account (e.g., MyNCBI for PubMed)
  • Log in with your NYU credentials
  • Open and "Make a Copy" to create your own tracker for your literature search strategies

4. Limit Your Results

Use database filters to limit your results based on your defined inclusion/exclusion criteria.  In addition to relying on the databases' categorical filters, you may also need to manually screen results.  

  • Limit to Article type, e.g.,:  "randomized controlled trial" OR multicenter study
  • Limit by publication years, age groups, language, etc.

NOTE: Many databases allow you to filter to "Full Text Only".  This filter is  not recommended . It excludes articles if their full text is not available in that particular database (CINAHL, PubMed, etc), but if the article is relevant, it is important that you are able to read its title and abstract, regardless of 'full text' status. The full text is likely to be accessible through another source (a different database, or Interlibrary Loan).  

  • Filters in PubMed
  • CINAHL Advanced Searching Tutorial

5. Download Citations

Selected citations and/or entire sets of search results can be downloaded from the database into a citation management tool. If you are conducting a systematic review that will require reporting according to PRISMA standards, a citation manager can help you keep track of the number of articles that came from each database, as well as the number of duplicate records.

In Zotero, you can create a Collection for the combined results set, and sub-collections for the results from each database you search.  You can then use Zotero's 'Duplicate Items" function to find and merge duplicate records.

File structure of a Zotero library, showing a combined pooled set, and sub folders representing results from individual databases.

  • Citation Managers - General Guide

6. Abstract and Analyze

  • Migrate citations to data collection/extraction tool
  • Screen Title/Abstracts for inclusion/exclusion
  • Screen and appraise full text for relevance, methods, 
  • Resolve disagreements by consensus

Covidence is a web-based tool that enables you to work with a team to screen titles/abstracts and full text for inclusion in your review, as well as extract data from the included studies.

Screenshot of the Covidence interface, showing Title and abstract screening phase.

  • Covidence Support
  • Critical Appraisal Tools
  • Data Extraction Tools

7. Create Flow Diagram

The PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) flow diagram is a visual representation of the flow of records through different phases of a systematic review.  It depicts the number of records identified, included and excluded.  It is best used in conjunction with the PRISMA checklist .

Example PRISMA diagram showing number of records identified, duplicates removed, and records excluded.

Example from: Stotz, S. A., McNealy, K., Begay, R. L., DeSanto, K., Manson, S. M., & Moore, K. R. (2021). Multi-level diabetes prevention and treatment interventions for Native people in the USA and Canada: A scoping review. Current Diabetes Reports, 2 (11), 46. https://doi.org/10.1007/s11892-021-01414-3

  • PRISMA Flow Diagram Generator (ShinyApp.io, Haddaway et al. )
  • PRISMA Diagram Templates  (Word and PDF)
  • Make a copy of the file to fill out the template
  • Image can be downloaded as PDF, PNG, JPG, or SVG
  • Covidence generates a PRISMA diagram that is automatically updated as records move through the review phases

8. Synthesize & Report Results

There are a number of reporting guideline available to guide the synthesis and reporting of results in systematic literature reviews.

It is common to organize findings in a matrix, also known as a Table of Evidence (ToE).

Example of a review matrix, using Microsoft Excel, showing the results of a systematic literature review.

  • Reporting Guidelines for Systematic Reviews
  • Download a sample template of a health sciences review matrix  (GoogleSheets)

Steps modified from: 

Cook, D. A., & West, C. P. (2012). Conducting systematic reviews in medical education: a stepwise approach.   Medical Education , 46 (10), 943–952.

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  • Next: What are Literature Reviews? >>
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  • How to Write a Literature Review | Guide, Examples, & Templates

How to Write a Literature Review | Guide, Examples, & Templates

Published on January 2, 2023 by Shona McCombes . Revised on September 11, 2023.

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 that you can later apply to your paper, thesis, or dissertation topic .

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 summarize sources—it analyzes, synthesizes , and critically evaluates to give a clear picture of the state of knowledge on the subject.

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Table of contents

What is the purpose of 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, free lecture slides, other interesting articles, frequently asked questions, introduction.

  • Quick Run-through
  • Step 1 & 2

When you write a thesis , dissertation , or research paper , you will likely 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 its scholarly context
  • Develop a theoretical framework and methodology for your research
  • Position your work in relation to other researchers and theorists
  • Show how your research addresses a gap or contributes to a debate
  • Evaluate the current state of research and demonstrate your knowledge of the scholarly debates around your topic.

Writing literature reviews is a particularly important skill if you want to apply for graduate school or pursue a career in research. We’ve written a step-by-step guide that you can follow below.

Literature review guide

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See an example

example of a medical literature review

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 problem and questions .

Make a list of keywords

Start by creating a list of keywords related to your research question. 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 as 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 useful 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 also use boolean operators to help narrow down your search.

Make sure to 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.

You likely won’t be able to read absolutely everything that has been written on your topic, so it will be necessary to evaluate which sources are most relevant to your research question.

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?
  • 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 use our template to summarize and evaluate sources you’re thinking about using. Click on either button below to download.

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 is important to keep track of your sources with citations to avoid plagiarism . It can be helpful to make an annotated bibliography , where you compile full citation 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.

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To begin organizing your literature review’s argument and structure, be sure you 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 organizing the body of a literature review. 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 summarizing sources in order.

Try to analyze 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 organize 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.

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, you can follow these tips:

  • Summarize and synthesize: give an overview of the main points of each source and combine them into a coherent whole
  • Analyze and interpret: don’t just paraphrase other researchers — add your own interpretations where possible, 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 transition words and topic sentences to draw connections, comparisons and contrasts

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

When you’ve finished writing and revising your literature review, don’t forget to proofread thoroughly before submitting. Not a language expert? Check out Scribbr’s professional proofreading services !

This article has been adapted into lecture slides that you can use to teach your students about writing a literature review.

Scribbr slides are free to use, customize, and distribute for educational purposes.

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If you want to know more about the research process , methodology , research bias , or statistics , make sure to check out some of our other articles with explanations and examples.

  • Sampling methods
  • Simple random sampling
  • Stratified sampling
  • Cluster sampling
  • Likert scales
  • Reproducibility

 Statistics

  • Null hypothesis
  • Statistical power
  • Probability distribution
  • Effect size
  • Poisson distribution

Research bias

  • Optimism bias
  • Cognitive bias
  • Implicit bias
  • Hawthorne effect
  • Anchoring bias
  • Explicit bias

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 thesis, dissertation , or research paper , in order to situate your work in relation to existing knowledge.

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

  • To familiarize 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 thesis or dissertation . After the introduction , it grounds your research in a scholarly field and leads directly to your theoretical framework or methodology .

A literature review is a survey of credible sources on a topic, often used in dissertations , theses, and research papers . Literature reviews give an overview of knowledge on a subject, helping you identify relevant theories and methods, as well as gaps in existing research. Literature reviews are set up similarly to other  academic texts , with an introduction , a main body, and a conclusion .

An  annotated bibliography is a list of  source references that has a short description (called an annotation ) for each of the sources. It is often assigned as part of the research process for a  paper .  

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How to Conduct a Literature Review (Health Sciences and Beyond)

What is a literature review, traditional (narrative) literature review, integrative literature review, systematic reviews, meta-analysis, scoping review.

  • Developing a Research Question
  • Selection Criteria
  • Database Search
  • Documenting Your Search
  • Organize Key Findings
  • Reference Management

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Related Guides

  • Systematic Reviews by Roy Brown Last Updated Oct 17, 2023 762 views this year
  • Write a Literature Review by John Glover Last Updated Oct 16, 2023 3708 views this year

A literature review provides an overview of what's been written about a specific topic. There are many different types of literature reviews. They vary in terms of comprehensiveness, types of study included, and purpose. 

The other pages in this guide will cover some basic steps to consider when conducting a traditional health sciences literature review. See below for a quick look at some of the more popular types of literature reviews.

For additional information on a variety of review methods, the following article provides an excellent overview.

Grant MJ, Booth A. A typology of reviews: an analysis of 14 review types and associated methodologies. Health Info Libr J. 2009 Jun;26(2):91-108. doi: 10.1111/j.1471-1842.2009.00848.x. Review. PubMed PMID: 19490148.

A traditional (narrative) literature review provides a quick overview of current studies. It helps explain why your study is important in the context of the literature, and can also help you identify areas that need further research. The rest of this guide will cover some basic steps to consider when conducting a traditional literature review. Click on the right thumbnail to see an excerpt from this type of literature review.

Integrative reviews "synthesize findings from different approaches, like experimental and non-experimental studies" ( ).  They may or may not be systematic reviews. Click on the right thumbnail to see an excerpt from this type of literature review.

Systematic reviews synthesize high quality empirical information to answer a given research question ( ). Conducting a systematic review involves following rigorous, predefined protocols that "minimise bias and ensure transparency" ( ). See our   for more information on what they are and how to conduct one. Click on the right thumbnail to see an excerpt from this type of literature review.

Meta-analyses are "the statistical integration of separate studies" ( ). They involve identifying similar studies and pooling their data to obtain a more accurate estimate of true effect size. A systematic review can include a meta-analysis. Click on the right thumbnail to see an excerpt from this type of literature review.

A scoping review involves a broad research question that explores the current evidence base ( ). It can help inform areas that are appropriate for a systematic review. Click on the right thumbnail to see an excerpt from this type of literature review.

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Literature Review Overview

What is a Literature Review? Why Are They Important?

A literature review is important because it presents the "state of the science" or accumulated knowledge on a specific topic. It summarizes, analyzes, and compares the available research, reporting study strengths and weaknesses, results, gaps in the research, conclusions, and authors’ interpretations.

Tips and techniques for conducting a literature review are described more fully in the subsequent boxes:

  • Literature review steps
  • Strategies for organizing the information for your review
  • Literature reviews sections
  • In-depth resources to assist in writing a literature review
  • Templates to start your review
  • Literature review examples

Literature Review Steps

example of a medical literature review

Graphic used with permission: Torres, E. Librarian, Hawai'i Pacific University

1. Choose a topic and define your research question

  • Try to choose a topic of interest. You will be working with this subject for several weeks to months.
  • Ideas for topics can be found by scanning medical news sources (e.g MedPage Today), journals / magazines, work experiences, interesting patient cases, or family or personal health issues.
  • Do a bit of background reading on topic ideas to familiarize yourself with terminology and issues. Note the words and terms that are used.
  • Develop a focused research question using PICO(T) or other framework (FINER, SPICE, etc - there are many options) to help guide you.
  • Run a few sample database searches to make sure your research question is not too broad or too narrow.
  • If possible, discuss your topic with your professor. 

2. Determine the scope of your review

The scope of your review will be determined by your professor during your program. Check your assignment requirements for parameters for the Literature Review.

  • How many studies will you need to include?
  • How many years should it cover? (usually 5-7 depending on the professor)
  • For the nurses, are you required to limit to nursing literature?

3. Develop a search plan

  • Determine which databases to search. This will depend on your topic. If you are not sure, check your program specific library website (Physician Asst / Nursing / Health Services Admin) for recommendations.
  • Create an initial search string using the main concepts from your research (PICO, etc) question. Include synonyms and related words connected by Boolean operators
  • Contact your librarian for assistance, if needed.

4. Conduct searches and find relevant literature

  • Keep notes as you search - tracking keywords and search strings used in each database in order to avoid wasting time duplicating a search that has already been tried
  • Read abstracts and write down new terms to search as you find them
  • Check MeSH or other subject headings listed in relevant articles for additional search terms
  • Scan author provided keywords if available
  • Check the references of relevant articles looking for other useful articles (ancestry searching)
  • Check articles that have cited your relevant article for more useful articles (descendancy searching). Both PubMed and CINAHL offer Cited By links
  • Revise the search to broaden or narrow your topic focus as you peruse the available literature
  • Conducting a literature search is a repetitive process. Searches can be revised and re-run multiple times during the process.
  • Track the citations for your relevant articles in a software citation manager such as RefWorks, Zotero, or Mendeley

5. Review the literature

  • Read the full articles. Do not rely solely on the abstracts. Authors frequently cannot include all results within the confines of an abstract. Exclude articles that do not address your research question.
  • While reading, note research findings relevant to your project and summarize. Are the findings conflicting? There are matrices available than can help with organization. See the Organizing Information box below.
  • Critique / evaluate the quality of the articles, and record your findings in your matrix or summary table. Tools are available to prompt you what to look for. (See Resources for Appraising a Research Study box on the HSA, Nursing , and PA guides )
  • You may need to revise your search and re-run it based on your findings.

6. Organize and synthesize

  • Compile the findings and analysis from each resource into a single narrative.
  • Using an outline can be helpful. Start broad, addressing the overall findings and then narrow, discussing each resource and how it relates to your question and to the other resources.
  • Cite as you write to keep sources organized.
  • Write in structured paragraphs using topic sentences and transition words to draw connections, comparisons, and contrasts.
  • Don't present one study after another, but rather relate one study's findings to another. Speak to how the studies are connected and how they relate to your work.

Organizing Information

Options to assist in organizing sources and information :

1. Synthesis Matrix

  • helps provide overview of the literature
  • information from individual sources is entered into a grid to enable writers to discern patterns and themes
  • article summary, analysis, or results
  • thoughts, reflections, or issues
  • each reference gets its own row
  • mind maps, concept maps, flowcharts
  • at top of page record PICO or research question
  • record major concepts / themes from literature
  • list concepts that branch out from major concepts underneath - keep going downward hierarchically, until most specific ideas are recorded
  • enclose concepts in circles and connect the concept with lines - add brief explanation as needed

3. Summary Table

  • information is recorded in a grid to help with recall and sorting information when writing
  • allows comparing and contrasting individual studies easily
  • purpose of study
  • methodology (study population, data collection tool)

Efron, S. E., & Ravid, R. (2019). Writing the literature review : A practical guide . Guilford Press.

Literature Review Sections

  • Lit reviews can be part of a larger paper / research study or they can be the focus of the paper
  • Lit reviews focus on research studies to provide evidence
  • New topics may not have much that has been published

* The sections included may depend on the purpose of the literature review (standalone paper or section within a research paper)

Standalone Literature Review (aka Narrative Review):

  • presents your topic or PICO question
  • includes the why of the literature review and your goals for the review.
  • provides background for your the topic and previews the key points
  • Narrative Reviews: tmay not have an explanation of methods.
  • include where the search was conducted (which databases) what subject terms or keywords were used, and any limits or filters that were applied and why - this will help others re-create the search
  • describe how studies were analyzed for inclusion or exclusion
  • review the purpose and answer the research question
  • thematically - using recurring themes in the literature
  • chronologically - present the development of the topic over time
  • methodological - compare and contrast findings based on various methodologies used to research the topic (e.g. qualitative vs quantitative, etc.)
  • theoretical - organized content based on various theories
  • provide an overview of the main points of each source then synthesize the findings into a coherent summary of the whole
  • present common themes among the studies
  • compare and contrast the various study results
  • interpret the results and address the implications of the findings
  • do the results support the original hypothesis or conflict with it
  • provide your own analysis and interpretation (eg. discuss the significance of findings; evaluate the strengths and weaknesses of the studies, noting any problems)
  • discuss common and unusual patterns and offer explanations
  •  stay away from opinions, personal biases and unsupported recommendations
  • summarize the key findings and relate them back to your PICO/research question
  • note gaps in the research and suggest areas for further research
  • this section should not contain "new" information that had not been previously discussed in one of the sections above
  • provide a list of all the studies and other sources used in proper APA 7

Literature Review as Part of a Research Study Manuscript:

  • Compares the study with other research and includes how a study fills a gap in the research.
  • Focus on the body of the review which includes the synthesized Findings and Discussion

Literature Reviews vs Systematic Reviews

Systematic Reviews are NOT the same as a Literature Review:

Literature Reviews:

  • Literature reviews may or may not follow strict systematic methods to find, select, and analyze articles, but rather they selectively and broadly review the literature on a topic
  • Research included in a Literature Review can be "cherry-picked" and therefore, can be very subjective

Systematic Reviews:

  • Systemic reviews are designed to provide a comprehensive summary of the evidence for a focused research question
  • rigorous and strictly structured, using standardized reporting guidelines (e.g. PRISMA, see link below)
  • uses exhaustive, systematic searches of all relevant databases
  • best practice dictates search strategies are peer reviewed
  • uses predetermined study inclusion and exclusion criteria in order to minimize bias
  • aims to capture and synthesize all literature (including unpublished research - grey literature) that meet the predefined criteria on a focused topic resulting in high quality evidence

Literature Review Examples

  • Breastfeeding initiation and support: A literature review of what women value and the impact of early discharge (2017). Women and Birth : Journal of the Australian College of Midwives
  • Community-based participatory research to promote healthy diet and nutrition and prevent and control obesity among African-Americans: A literature review (2017). Journal of Racial and Ethnic Health Disparities

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  • Vitamin D deficiency in individuals with a spinal cord injury: A literature review (2017). Spinal Cord

Resources for Writing a Literature Review

These sources have been used in developing this guide.

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Resources Used on This Page

Aveyard, H. (2010). Doing a literature review in health and social care : A practical guide . McGraw-Hill Education.

Purdue Online Writing Lab. (n.d.). Writing a literature review . Purdue University. https://owl.purdue.edu/owl/research_and_citation/conducting_research/writing_a_literature_review.html

Torres, E. (2021, October 21). Nursing - graduate studies research guide: Literature review. Hawai'i Pacific University Libraries. Retrieved January 27, 2022, from https://hpu.libguides.com/c.php?g=543891&p=3727230

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  • Types of Literature Reviews
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  • The Pandora's Box of Evidence Synthesis and the case for a living Evidence Synthesis Taxonomy | BMJ Evidence-Based Medicine, 2023
  • Meeting the review family: exploring review types and associated information retrieval requirements | Health Information and Libraries Journal, 2019
  • A typology of reviews: an analysis of 14 review types and associated methodologies | Health Information and Libraries Journal, 2009
  • Conceptual recommendations for selecting the most appropriate knowledge synthesis method to answer research questions related to complex evidence | Journal of Clinical Epidemiology, 2016
  • Methods for knowledge synthesis: an overview | Heart & Lung: The Journal of Critical Care, 2014
  • Not sure what type of review to conduct? Brief descriptions of each type plus tools to help you decide

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  • Ten simple rules for writing a literature review | PLoS Computational Biology, 2013
  • The Purpose, Process, and Methods of Writing a Literature Review | AORN Journal. 2016
  • Why, When, Who, What, How, and Where for Trainees Writing Literature Review Articles. | Annals of Biomed Engineering, 2019
  • So You Want to Write a Narrative Review Article? | Journal of Cardiothoracic and Anesthesia, 2021
  • An Introduction to Writing Narrative and Systematic Reviews - Tasks, Tips and Traps for Aspiring Authors | Heart, Lung, and Circulation, 2018

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  • The Literature Review: A Foundation for High-Quality Medical Education Research | Journal of Graduate Medical Education, 2016
  • Writing an effective literature review : Part I: Mapping the gap | Perspectives on Medical Education, 2018
  • Writing an effective literature review : Part II: Citation technique | Perspectives on Medical Education, 2018

Types of Reviews

Label Description Search Appraisal Synthesis Analysis
Critical Review Aims to demonstrate writer has extensively researched literature and critically evaluated its quality. Goes beyond mere description to include degree of analysis and conceptual innovation. Typically results in hypothesis or model Seeks to identify most significant items in the field No formal quality assessment. Attempts to evaluate according to contribution Typically narrative, perhaps conceptual or chronological Significant component: seeks to identify conceptual contribution to embody existing or derive new theory
Literature Review Generic term: published materials that provide examination of recent or current literature. Can cover wide range of subjects at various levels of completeness and comprehensiveness. May include research findings May or may not include comprehensive searching May or may not include quality assessment Typically narrative Analysis may be chronological, conceptual, thematic, etc.
Mapping review/ systematic map Map out and categorize existing literature from which to commission further reviews and/or primary research by identifying gaps in research literature Completeness of searching determined by time/scope constraints No formal quality assessment May be graphical and tabular Characterizes quantity and quality of literature, perhaps by study design and other key features. May identify need for primary or secondary research
Meta-analysis Technique that statistically combines the results of quantitative studies to provide a more precise effect of the results Aims for exhaustive, comprehensive searching. May use funnel plot to assess completeness Quality assessment may determine inclusion/exclusion and/or sensitivity analyses Graphical and tabular with narrative commentary Numerical analysis of measures of effect assuming absence of heterogeneity
Mixed studies review/mixed methods review Refers to any combination of methods where one significant component is a literature review (usually systematic). Within a review context it refers to a combination of review approaches for example combining quantitative with qualitative research or outcome with process studies Requires either very sensitive search to retrieve all studies or separately conceived quantitative and qualitative strategies Requires either a generic appraisal instrument or separate appraisal processes with corresponding checklists Typically both components will be presented as narrative and in tables. May also employ graphical means of integrating quantitative and qualitative studies Analysis may characterise both literatures and look for correlations between characteristics or use gap analysis to identify aspects absent in one literature but missing in the other
Overview Generic term: summary of the [medical] literature that attempts to survey the literature and describe its characteristics May or may not include comprehensive searching (depends whether systematic overview or not) May or may not include quality assessment (depends whether systematic overview or not) Synthesis depends on whether systematic or not. Typically narrative but may include tabular features Analysis may be chronological, conceptual, thematic, etc.
Qualitative systematic review/qualitative evidence synthesis Method for integrating or comparing the findings from qualitative studies. It looks for ‘themes’ or ‘constructs’ that lie in or across individual qualitative studies May employ selective or purposive sampling Quality assessment typically used to mediate messages not for inclusion/exclusion Qualitative, narrative synthesis Thematic analysis, may include conceptual models
Rapid review Assessment of what is already known about a policy or practice issue, by using systematic review methods to search and critically appraise existing research Completeness of searching determined by time constraints Time-limited formal quality assessment Typically narrative and tabular Quantities of literature and overall quality/direction of effect of literature
Scoping review Preliminary assessment of potential size and scope of available research literature. Aims to identify nature and extent of research evidence (usually including ongoing research) Completeness of searching determined by time/scope constraints. May include research in progress No formal quality assessment Typically tabular with some narrative commentary Characterizes quantity and quality of literature, perhaps by study design and other key features. Attempts to specify a viable review
State-of-the-art review Tend to address more current matters in contrast to other combined retrospective and current approaches. May offer new perspectives on issue or point out area for further research Aims for comprehensive searching of current literature No formal quality assessment Typically narrative, may have tabular accompaniment Current state of knowledge and priorities for future investigation and research
Systematic review Seeks to systematically search for, appraise and synthesis research evidence, often adhering to guidelines on the conduct of a review Aims for exhaustive, comprehensive searching Quality assessment may determine inclusion/exclusion Typically narrative with tabular accompaniment What is known; recommendations for practice. What remains unknown; uncertainty around findings, recommendations for future research
Systematic search and review Combines strengths of critical review with a comprehensive search process. Typically addresses broad questions to produce ‘best evidence synthesis’ Aims for exhaustive, comprehensive searching May or may not include quality assessment Minimal narrative, tabular summary of studies What is known; recommendations for practice. Limitations
Systematized review Attempt to include elements of systematic review process while stopping short of systematic review. Typically conducted as postgraduate student assignment May or may not include comprehensive searching May or may not include quality assessment
Typically narrative with tabular accompaniment  

Reproduced from Grant MJ, Booth A. A typology of reviews: an analysis of 14 review types and associated methodologies . Health Info Libr J. 2009 Jun;26(2):91-108. doi: 10.1111/j.1471-1842.2009.00848.x

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A necessary skill for any doctor

What causes disease, which drug is best, does this patient need surgery, and what is the prognosis? Although experience helps in answering these questions, ultimately they are best answered by evidence based medicine. But how do you assess the evidence? As a medical student, and throughout your career as a doctor, critical appraisal of published literature is an important skill to develop and refine. At medical school you will repeatedly appraise published literature and write literature reviews. These activities are commonly part of a special study module, research project for an intercalated degree, or another type of essay based assignment.

Formulating a question

Literature reviews are most commonly performed to help answer a particular question. While you are at medical school, there will usually be some choice regarding the area you are going to review.

Once you have identified a subject area for review, the next step is to formulate a specific research question. This is arguably the most important step because a clear question needs to be defined from the outset, which you aim to answer by doing the review. The clearer the question, the more likely it is that the answer will be clear too. It is important to have discussions with your supervisor when formulating a research question as his or her input will be invaluable. The research question must be objective and concise because it is easier to search through the evidence with a clear question. The question also needs to be feasible. What is the point in having a question for which no published evidence exists? Your supervisor’s input will ensure you are not trying to answer an unrealistic question. Finally, is the research question clinically important? There are many research questions that may be answered, but not all of them will …

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Further reading & examples

Journal articles.

  • Examples of literature reviews
  • Articles on literature reviews
  • Family needs and involvement in the intensive care unit: a literature review Al-Mutair, A. S., Plummer, V., O'Brien, A., & Clerehan, R. (2013). Family needs and involvement in the intensive care unit: a literature review. Journal of Clinical Nursing, 22(13/14), 1805-1817. doi:10.1111/jocn.12065
  • A literature review exploring how healthcare professionals contribute to the assessment and control of postoperative pain in older people Brown, D. (2004). A literature review exploring how healthcare professionals contribute to the assessment and control of postoperative pain in older people. Journal of Clinical Nursing, 13(6b), 74-90. doi:10.1111/j.1365-2702.2004.01047.x
  • Effects of team coordination during cardiopulmonary resuscitation: A systematic review of the literature Castelao, E. F., Russo, S. G., Riethmüller, M., & Boos, M. (2013). Effects of team coordination during cardiopulmonary resuscitation: A systematic review of the literature. Journal of Critical Care, 28(4), 504-521. doi:10.1016/j.jcrc.2013.01.005
  • Literature review: Eating and drinking in labour Hunt, L. (2013). Literature review: Eating and drinking in labour. British Journal of Midwifery, 21(7), 499-502.
  • Collaboration between hospital physicians and nurses: An integrated literature review Tang, C. J., Chan, S. W., Zhou, W. T., & Liaw, S. Y. (2013). Collaboration between hospital physicians and nurses: An integrated literature review. International Nursing Review, 60(3), 291-302. doi:10.1111/inr.12034
  • A systematic literature review of Releasing Time to Care: The Productive Ward Wright, S., & McSherry, W. (2013). A systematic literature review of Releasing Time to Care: The Productive Ward. Journal of Clinical Nursing, 22(9/10), 1361-1371. doi:10.1111/jocn.12074
  • Learning how to undertake a systematic review: part 1. Bettany-Saltikov, J. (2010). Learning how to undertake a systematic review: part 1. Nursing Standard, 24(50), 47-56.
  • Users' guide to the surgical literature: how to use a systematic literature review and meta-analysis Bhandari, M., Devereaux, P. J., Montori, V., Cinà, C., Tandan, V., & Guyatt, G. H. (2004). Users' guide to the surgical literature: how to use a systematic literature review and meta-analysis. Canadian Journal of Surgery, 47(1), 60-67.
  • Strategies for the construction of a critical review of the literature Carnwell, R., & Daly, W. (2001). Strategies for the construction of a critical review of the literature. Nurse Education in Practice, 1(2), 57-63.
  • Thoughts about conceptual models, theories, and literature reviews Fawcett, J. (2013). Thoughts about conceptual models, theories, and literature reviews. Nursing Science Quarterly, 26(3), 285-288. doi:10.1177/0894318413489156
  • Turn a stack of papers into a literature review: useful tools for beginners Talbot, L., & Verrinder, G. (2008). Turn a Stack of Papers into a Literature Review: Useful Tools for Beginners. Focus on health professional education: a multi-disciplinary journal, 10(1), 51-58.

example of a medical literature review

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Writing in the Health Sciences: Research and Lit Reviews

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What Is a Literature Review?

In simple terms, a literature review investigates the available information on a certain topic. It may be only a knowledge survey with an intentional focus. However, it is often a well-organized examination of the existing research which evaluates each resource in a systematic way. Often a lit review will involve a series of inclusion/exclusion criteria or an assessment rubric which examines the research in-depth. Below are some interesting sources to consider.

example of a medical literature review

The Writing Center's Literature Reviews - UNC-Chapel Hill's writing center explains some of the key criteria involved in doing a literature review.

Literature Review vs. Systematic Review - This recent article details the difference between a literature review and a systematic review. Though the two share similar attributes, key differences are identified here.

Literature Review Steps

1. Identify a research question. For example: "Does the use of warfarin in elderly patients recovering from myocardial infarction help prevent stroke?"

2. Consider which databases might provide information for your topic. Often PubMed or CINAHL will cover a wide spectrum of biomedical issues. However, other databases and grey literature sources may specialize in certain disciplines. Embase is generally comprehensive but also specializes in pharmacological interventions.

3. Select the major subjects or ideas from your question.  Focus in on the particular concepts involved in your research. Then brainstorm synonyms and related terminology for these topics.

4. Look for the  preferred indexing terms for each concept in your question. This is especially important with databases such as PubMed, CINAHL, or Scopus where headings within the MeSH database or under the Emtree umbrella are present.  For example, the above question's keywords such as " warfarin " or "myocardial infarction" can involve related terminology or subject headings such as "anti-coagulants" or "cardiovascular disease."

5. Build your search using boolean operators. Combine the synonyms in your database using boolean operators such as AND or OR. Sometimes it is necessary to research parts of a question rather than the whole. So you might link searches for things like the preventive effects of anti-coagulants with stroke or embolism, then AND these results with the therapy for patients with cardiovascular disease.

6. Filter and save your search results from the first database (do this for all databases). This may be a short list because of your topic's limitations, but it should be no longer than 15 articles for an initial search. Make sure your list is saved or archived and presents you with what's needed to access the full text.

7. Use the same process with the next databases on your list. But pay attention to how certain major headings may alter the terminology. "Stroke" may have a suggested term of "embolism" or even "cerebrovascular incident" depending on the database.

8. Read through the material for inclusion/exclusion . Based on your project's criteria and objective, consider which studies or reviews deserve to be included and which should be discarded. Make sure the information you have permits you to go forward. 

9. Write the literature review. Begin by summarizing why your research is important and explain why your approach will help fill gaps in current knowledge. Then incorporate how the information you've selected will help you to do this. You do not need to write about all of the included research you've chosen, only the most pe rtinent.

10. Select the most relevant literature for inclusion in the body of your report. Choose the articles and data sets that are most particularly relevant to your experimental approach. Consider how you might arrange these sources in the body of your draft. 

Library Books

example of a medical literature review

Call #: WZ 345 G192h 2011

ISBN #: 9780763771867

This book details a practical, step-by-step method for conducting a literature review in the health sciences. Aiming to  synthesize the information while also analyzing it, the Matrix Indexing System enables users to establish a  structured process for tracking, organizing and integrating the knowledge within a collection.

Key Research Databases

PubMed -  The premier medical database for review articles in medicine, nursing, healthcare, other related biomedical disciplines. PubMed contains over 20 million citations and can be navigated through multiple database capabilities and searching strategies.

CINAHL Ultimate - Offers comprehensive coverage of health science literature. CINAHL is particularly useful for those researching the allied disciplines of nursing, medicine, and pharmaceutical sciences.

Scopus - Database with over 12 million abstracts and citations which include peer-reviewed titles from international and Open Access journals. Also includes interactive bibliometrics and researcher profiling.

Embase - Elsevier's fully interoperable database of both Medline and Emtree-indexed articles. Embase also specializes in pharmacologic interventions.

Cochrane - Selected evidence-based medicine resources from the Cochrane Collaboration that includes peer-reviewed systematic reviews and randomized controlled trials. Access this database through OVID with TTUHSC Libraries.

DARE - Literally the Datatase of Abstracts of Reviews of Effectiveness, this collection of systematic reviews and other evidence-based research contains critical assessments from a wide variety of medical journals.

TRIP - This TRIP database is structured according to the level of evidence for its EBM content. It allows users to quickly and easily locate high-quality, accredited medical literature for clinical and research purposes.

Web of Science - Contains bibliographic articles and data from a wide variety of publications in the life sciences and other fields. Also, see this link for conducting a lit review exclusively within Web of Science.

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15 Literature Review Examples

15 Literature Review Examples

Chris Drew (PhD)

Dr. Chris Drew is the founder of the Helpful Professor. He holds a PhD in education and has published over 20 articles in scholarly journals. He is the former editor of the Journal of Learning Development in Higher Education. [Image Descriptor: Photo of Chris]

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literature review examples, types, and definition, explained below

Literature reviews are a necessary step in a research process and often required when writing your research proposal . They involve gathering, analyzing, and evaluating existing knowledge about a topic in order to find gaps in the literature where future studies will be needed.

Ideally, once you have completed your literature review, you will be able to identify how your research project can build upon and extend existing knowledge in your area of study.

Generally, for my undergraduate research students, I recommend a narrative review, where themes can be generated in order for the students to develop sufficient understanding of the topic so they can build upon the themes using unique methods or novel research questions.

If you’re in the process of writing a literature review, I have developed a literature review template for you to use – it’s a huge time-saver and walks you through how to write a literature review step-by-step:

Get your time-saving templates here to write your own literature review.

Literature Review Examples

For the following types of literature review, I present an explanation and overview of the type, followed by links to some real-life literature reviews on the topics.

1. Narrative Review Examples

Also known as a traditional literature review, the narrative review provides a broad overview of the studies done on a particular topic.

It often includes both qualitative and quantitative studies and may cover a wide range of years.

The narrative review’s purpose is to identify commonalities, gaps, and contradictions in the literature .

I recommend to my students that they should gather their studies together, take notes on each study, then try to group them by themes that form the basis for the review (see my step-by-step instructions at the end of the article).

Example Study

Title: Communication in healthcare: a narrative review of the literature and practical recommendations

Citation: Vermeir, P., Vandijck, D., Degroote, S., Peleman, R., Verhaeghe, R., Mortier, E., … & Vogelaers, D. (2015). Communication in healthcare: a narrative review of the literature and practical recommendations. International journal of clinical practice , 69 (11), 1257-1267.

Source: https://onlinelibrary.wiley.com/doi/pdf/10.1111/ijcp.12686  

Overview: This narrative review analyzed themes emerging from 69 articles about communication in healthcare contexts. Five key themes were found in the literature: poor communication can lead to various negative outcomes, discontinuity of care, compromise of patient safety, patient dissatisfaction, and inefficient use of resources. After presenting the key themes, the authors recommend that practitioners need to approach healthcare communication in a more structured way, such as by ensuring there is a clear understanding of who is in charge of ensuring effective communication in clinical settings.

Other Examples

  • Burnout in United States Healthcare Professionals: A Narrative Review (Reith, 2018) – read here
  • Examining the Presence, Consequences, and Reduction of Implicit Bias in Health Care: A Narrative Review (Zestcott, Blair & Stone, 2016) – read here
  • A Narrative Review of School-Based Physical Activity for Enhancing Cognition and Learning (Mavilidi et al., 2018) – read here
  • A narrative review on burnout experienced by medical students and residents (Dyrbye & Shanafelt, 2015) – read here

2. Systematic Review Examples

This type of literature review is more structured and rigorous than a narrative review. It involves a detailed and comprehensive plan and search strategy derived from a set of specified research questions.

The key way you’d know a systematic review compared to a narrative review is in the methodology: the systematic review will likely have a very clear criteria for how the studies were collected, and clear explanations of exclusion/inclusion criteria. 

The goal is to gather the maximum amount of valid literature on the topic, filter out invalid or low-quality reviews, and minimize bias. Ideally, this will provide more reliable findings, leading to higher-quality conclusions and recommendations for further research.

You may note from the examples below that the ‘method’ sections in systematic reviews tend to be much more explicit, often noting rigid inclusion/exclusion criteria and exact keywords used in searches.

Title: The importance of food naturalness for consumers: Results of a systematic review  

Citation: Roman, S., Sánchez-Siles, L. M., & Siegrist, M. (2017). The importance of food naturalness for consumers: Results of a systematic review. Trends in food science & technology , 67 , 44-57.

Source: https://www.sciencedirect.com/science/article/pii/S092422441730122X  

Overview: This systematic review included 72 studies of food naturalness to explore trends in the literature about its importance for consumers. Keywords used in the data search included: food, naturalness, natural content, and natural ingredients. Studies were included if they examined consumers’ preference for food naturalness and contained empirical data. The authors found that the literature lacks clarity about how naturalness is defined and measured, but also found that food consumption is significantly influenced by perceived naturalness of goods.

  • A systematic review of research on online teaching and learning from 2009 to 2018 (Martin, Sun & Westine, 2020) – read here
  • Where Is Current Research on Blockchain Technology? (Yli-Huumo et al., 2016) – read here
  • Universities—industry collaboration: A systematic review (Ankrah & Al-Tabbaa, 2015) – read here
  • Internet of Things Applications: A Systematic Review (Asghari, Rahmani & Javadi, 2019) – read here

3. Meta-analysis

This is a type of systematic review that uses statistical methods to combine and summarize the results of several studies.

Due to its robust methodology, a meta-analysis is often considered the ‘gold standard’ of secondary research , as it provides a more precise estimate of a treatment effect than any individual study contributing to the pooled analysis.

Furthermore, by aggregating data from a range of studies, a meta-analysis can identify patterns, disagreements, or other interesting relationships that may have been hidden in individual studies.

This helps to enhance the generalizability of findings, making the conclusions drawn from a meta-analysis particularly powerful and informative for policy and practice.

Title: Cholesterol and Alzheimer’s Disease Risk: A Meta-Meta-Analysis

Citation: Sáiz-Vazquez, O., Puente-Martínez, A., Ubillos-Landa, S., Pacheco-Bonrostro, J., & Santabárbara, J. (2020). Cholesterol and Alzheimer’s disease risk: a meta-meta-analysis. Brain sciences, 10(6), 386.

Source: https://doi.org/10.3390/brainsci10060386  

O verview: This study examines the relationship between cholesterol and Alzheimer’s disease (AD). Researchers conducted a systematic search of meta-analyses and reviewed several databases, collecting 100 primary studies and five meta-analyses to analyze the connection between cholesterol and Alzheimer’s disease. They find that the literature compellingly demonstrates that low-density lipoprotein cholesterol (LDL-C) levels significantly influence the development of Alzheimer’s disease.

  • The power of feedback revisited: A meta-analysis of educational feedback research (Wisniewski, Zierer & Hattie, 2020) – read here
  • How Much Does Education Improve Intelligence? A Meta-Analysis (Ritchie & Tucker-Drob, 2018) – read here
  • A meta-analysis of factors related to recycling (Geiger et al., 2019) – read here
  • Stress management interventions for police officers and recruits (Patterson, Chung & Swan, 2014) – read here

Other Types of Reviews

  • Scoping Review: This type of review is used to map the key concepts underpinning a research area and the main sources and types of evidence available. It can be undertaken as stand-alone projects in their own right, or as a precursor to a systematic review.
  • Rapid Review: This type of review accelerates the systematic review process in order to produce information in a timely manner. This is achieved by simplifying or omitting stages of the systematic review process.
  • Integrative Review: This review method is more inclusive than others, allowing for the simultaneous inclusion of experimental and non-experimental research. The goal is to more comprehensively understand a particular phenomenon.
  • Critical Review: This is similar to a narrative review but requires a robust understanding of both the subject and the existing literature. In a critical review, the reviewer not only summarizes the existing literature, but also evaluates its strengths and weaknesses. This is common in the social sciences and humanities .
  • State-of-the-Art Review: This considers the current level of advancement in a field or topic and makes recommendations for future research directions. This type of review is common in technological and scientific fields but can be applied to any discipline.

How to Write a Narrative Review (Tips for Undergrad Students)

Most undergraduate students conducting a capstone research project will be writing narrative reviews. Below is a five-step process for conducting a simple review of the literature for your project.

  • Search for Relevant Literature: Use scholarly databases related to your field of study, provided by your university library, along with appropriate search terms to identify key scholarly articles that have been published on your topic.
  • Evaluate and Select Sources: Filter the source list by selecting studies that are directly relevant and of sufficient quality, considering factors like credibility , objectivity, accuracy, and validity.
  • Analyze and Synthesize: Review each source and summarize the main arguments  in one paragraph (or more, for postgrad). Keep these summaries in a table.
  • Identify Themes: With all studies summarized, group studies that share common themes, such as studies that have similar findings or methodologies.
  • Write the Review: Write your review based upon the themes or subtopics you have identified. Give a thorough overview of each theme, integrating source data, and conclude with a summary of the current state of knowledge then suggestions for future research based upon your evaluation of what is lacking in the literature.

Literature reviews don’t have to be as scary as they seem. Yes, they are difficult and require a strong degree of comprehension of academic studies. But it can be feasibly done through following a structured approach to data collection and analysis. With my undergraduate research students (who tend to conduct small-scale qualitative studies ), I encourage them to conduct a narrative literature review whereby they can identify key themes in the literature. Within each theme, students can critique key studies and their strengths and limitations , in order to get a lay of the land and come to a point where they can identify ways to contribute new insights to the existing academic conversation on their topic.

Ankrah, S., & Omar, A. T. (2015). Universities–industry collaboration: A systematic review. Scandinavian Journal of Management, 31(3), 387-408.

Asghari, P., Rahmani, A. M., & Javadi, H. H. S. (2019). Internet of Things applications: A systematic review. Computer Networks , 148 , 241-261.

Dyrbye, L., & Shanafelt, T. (2016). A narrative review on burnout experienced by medical students and residents. Medical education , 50 (1), 132-149.

Geiger, J. L., Steg, L., Van Der Werff, E., & Ünal, A. B. (2019). A meta-analysis of factors related to recycling. Journal of environmental psychology , 64 , 78-97.

Martin, F., Sun, T., & Westine, C. D. (2020). A systematic review of research on online teaching and learning from 2009 to 2018. Computers & education , 159 , 104009.

Mavilidi, M. F., Ruiter, M., Schmidt, M., Okely, A. D., Loyens, S., Chandler, P., & Paas, F. (2018). A narrative review of school-based physical activity for enhancing cognition and learning: The importance of relevancy and integration. Frontiers in psychology , 2079.

Patterson, G. T., Chung, I. W., & Swan, P. W. (2014). Stress management interventions for police officers and recruits: A meta-analysis. Journal of experimental criminology , 10 , 487-513.

Reith, T. P. (2018). Burnout in United States healthcare professionals: a narrative review. Cureus , 10 (12).

Ritchie, S. J., & Tucker-Drob, E. M. (2018). How much does education improve intelligence? A meta-analysis. Psychological science , 29 (8), 1358-1369.

Roman, S., Sánchez-Siles, L. M., & Siegrist, M. (2017). The importance of food naturalness for consumers: Results of a systematic review. Trends in food science & technology , 67 , 44-57.

Sáiz-Vazquez, O., Puente-Martínez, A., Ubillos-Landa, S., Pacheco-Bonrostro, J., & Santabárbara, J. (2020). Cholesterol and Alzheimer’s disease risk: a meta-meta-analysis. Brain sciences, 10(6), 386.

Vermeir, P., Vandijck, D., Degroote, S., Peleman, R., Verhaeghe, R., Mortier, E., … & Vogelaers, D. (2015). Communication in healthcare: a narrative review of the literature and practical recommendations. International journal of clinical practice , 69 (11), 1257-1267.

Wisniewski, B., Zierer, K., & Hattie, J. (2020). The power of feedback revisited: A meta-analysis of educational feedback research. Frontiers in Psychology , 10 , 3087.

Yli-Huumo, J., Ko, D., Choi, S., Park, S., & Smolander, K. (2016). Where is current research on blockchain technology?—a systematic review. PloS one , 11 (10), e0163477.

Zestcott, C. A., Blair, I. V., & Stone, J. (2016). Examining the presence, consequences, and reduction of implicit bias in health care: a narrative review. Group Processes & Intergroup Relations , 19 (4), 528-542

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Writing a Literature Review: Examples & Tutorials

  • Phase 1: Scope of Review
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Examples of Lit. Reviews

Sample Literature Review -Here is a sample literature review written by a librarian at American University Library.

Deshmukh, Marion F. " The Visual Arts and Cultural Migration in the 1930s and 1940s: A Literature Review. " Central European History (Cambridge University Press / UK) 41.4 (2008): 569-604. Dunjó, Jordi, et al. " Hazard and Operability (HAZOP) Analysis. A Literature Review ." Journal of Hazardous Materials 173.1-3 (2010): 19-32. Gibbons, Susan. " Understanding Empathy as a Complex Construct: A Review of the Literature ." Clinical Social Work Journal 39.3 (2011): 243-52.

Liddle, H. A. (2004). Family-based therapies for adolescent alcohol and drug use: Research contributions and future research needs.   Addiction , 99 (Suppl.2), 76-92.

Mayer, David J. " Acupuncture: An Evidence-Based Review of the Clinical Literature ." Annual Review of Medicine 51:1 (2000): 49-63.

Meyer, Sebastian, Bruno Glaser, and Peter Quicker. " Technical, Economical, and Climate-Related Aspects of Biochar Production Technologies: A Literature Review. " Environmental science & technology 45.22 (2011): 9473-83.

  • Writing the Literature Review Part I Defines what a literature review is - and is not.
  • Writing the Literature Review Part II Organizing sources, basic steps in the writing process.
  • Literature Review Overview for Graduate Students Understand how studies relate to one another, how your own ideas fit within the existing literature.
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The “PP-ICONS” approach will help you separate the clinical wheat from the chaff in mere minutes .

ROBERT J. FLAHERTY, MD

Fam Pract Manag. 2004;11(5):47-52

Keeping up with the latest advances in diagnosis and treatment is a challenge we all face as phycians. We need information that is both valid (that is, accurate and correct) and relevant to our patients and practices. While we have many sources of clinical information, such as CME lectures, textbooks, pharmaceutical advertising, pharmaceutical representatives and colleagues, we often turn to journal articles for the most current clinical information.

Unfortunately, a great deal of research reported in journal articles is poorly done, poorly analyzed or both, and thus is not valid. A great deal of research is also irrelevant to our patients and practices. Separating the clinical wheat from the chaff can take skills that many of us never were taught.

Reading the abstract is often sufficient when evaluating an article using the PP-ICONS approach.

The most relevant studies will involve outcomes that matter to patients (e.g., morbidity, mortality and cost) versus outcomes that matter to physiologists (e.g., blood pressure, blood sugar or cholesterol levels).

Ignore the relative risk reduction, as it overstates research findings and will mislead you.

The article “Making Evidence-Based Medicine Doable in Everyday Practice” in the February 2004 issue of FPM describes several organizations that can help us. These organizations, such as the Cochrane Library, Bandolier and Clinical Evidence, develop clinical questions and then review one or more journal articles to identify the best available evidence that answers the question, with a focus on the quality of the study, the validity of the results and the relevance of the findings to everyday practice. These organizations provide a very valuable service, and the number of important clinical questions that they have studied has grown steadily over the past five years. (See “Four steps to an evidence-based answer.” )

FOUR STEPS TO AN EVIDENCE-BASED ANSWER

When faced with a clinical question, follow these steps to find an evidence-based answer:

Search the Web site of one of the evidence review organizations, such as Cochrane (http://www.cochrane.org/cochrane/revabstr/mainindex.htm), Bandolier ( http://www.jr2.ox.ac.uk/bandolier ) or Clinical Evidence ( http://www.clinicalevidence.com ), described in “Making Evidence-Based Medicine Doable in Everyday Practice,” FPM, February 2004, page 51 . You can also search the TRIP+ Web site ( http://www.tripdatabase.com ), which simultaneously searches the databases of many of the review organizations. If you find a systematic review or meta-analysis by one of these organizations, you can be confident that you’ve found the best evidence available.

If you don’t find the information you need through step 1, search for meta-analyses and systematic reviews using the PubMed Web site (see the tutorial at http://www.nlm.nih.gov/bsd/pubmed_tutorial/m1001.html ). Most of the recent abstracts found on PubMed provide enough information for you to determine the validity and relevance of the findings. If needed, you can get a copy of the full article through your hospital library or the journal’s Web site.

If you cannot find a systematic review or meta-analysis on PubMed, look for a randomized controlled trial (RCT). The RCT is the “gold standard” in medical research. Case reports, cohort studies and other research methods simply are not good enough to use for making patient care decisions.

Once you find the article you need, use the PP-ICONS approach to evaluate its usefulness to your patient.

If you find a systematic review or meta-analysis done by one of these organizations, you can feel confident that you have found the current best evidence. However, these organizations have not asked all of the common clinical questions yet, and you will frequently be faced with finding the pertinent articles and determining for yourself whether they are valuable. This is where the PP-ICONS approach can help.

What is PP-ICONS?

When you find a systematic review, meta-analysis or randomized controlled trial while reading your clinical journals or searching PubMed ( http://www.ncbi.nlm.nih.gov/entrez/query.fcgi ), you need to determine whether it is valid and relevant. There are many different ways to analyze an abstract or journal article, some more rigorous than others. 1 , 2 I have found a simple but effective way to identify a valid or relevant article within a couple of minutes, ensuring that I can use or discard the conclusions with confidence. This approach works well on articles regarding treatment and prevention, and can also be used with articles on diagnosis and screening.

The most important information to look for when reviewing an article can be summarized by the acronym “PP-ICONS,” which stands for the following:

Patient or population,

Intervention,

Comparison,

Number of subjects,

Statistics.

For example, imagine that you just saw a nine-year-old patient in the office with common warts on her hands, an ideal candidate for your usual cryotherapy. Her mother had heard about treating warts with duct tape and wondered if you would recommend this treatment. You promised to call Mom back after you had a chance to investigate this rather odd treatment.

When you get a free moment, you write down your clinical question: “Is duct tape an effective treatment for warts in children?” Writing down your clinical question is useful, as it can help you clarify exactly what you are looking for. Use the PPICO parts of the acronym to help you write your clinical question; this is actually how many researchers develop their research questions.

You search Cochrane and Bandolier without success, so now you search PubMed, which returns an abstract for the following article: “Focht DR 3rd, Spicer C, Fairchok MP. The efficacy of duct tape vs cryotherapy in the treatment of verruca vulgaris (the common wart). Arch Pediatr Adolesc Med . 2002 Oct;156(10):971-974.”

You decide to apply PP-ICONS to this abstract (see "Abstract from PubMed" ) to determine if the information is both valid and relevant.

ABSTRACT FROM PUBMED

Using the PP-ICONS approach, physicians can evaluate the validity and relevance of clinical articles in minutes using only the abstract, such as this one, obtained free online from PubMed, http://www.ncbi. nlm.nih.gov/entrez/query.fcgi. The author uses this abstract to evaluate the use of duct tape to treat common warts.

example of a medical literature review

Problem. The first P in PP-ICONS is for “problem,” which refers to the clinical condition that was studied. From the abstract, it is clear that the researchers studied the same problem you are interested in, which is important since flat warts or genital warts may have responded differently. Obviously, if the problem studied were not sufficiently similar to your clinical problem, the results would not be relevant.

Patient or population. Next, consider the patient or population. Is the study group similar to your patient or practice? Are they primary care patients, for example, or are they patients who have been referred to a tertiary care center? Are they of a similar age and gender? In this case, the researchers studied children and young adults in outpatient clinics, which is similar to your patient population. If the patients in the study are not similar to your patient, for example if they are sicker, older, a different gender or more clinically complicated, the results might not be relevant.

Intervention. The intervention could be a diagnostic test or a treatment. Make sure the intervention is the same as what you are looking for. The patient’s mother was asking about duct tape for warts, so this is a relevant study.

Comparison. The comparison is what the intervention is tested against. It could be a different diagnostic test or another therapy, such as cryotherapy in this wart study. It could even be placebo or no treatment. Make sure the comparison fits your question. You usually use cryotherapy for common warts, so this is a relevant comparison.

Outcome. The outcome is particularly important. Many outcomes are “disease-oriented outcomes,” which are based on “disease-oriented evidence” (DOEs). DOEs usually reflect changes in physiologic parameters, such as blood pressure, blood sugar, cholesterol, etc. We have long assumed that improving the physiologic parameters of a disease will result in a better disease outcome, but that is not necessarily true. For instance, finasteride can improve urinary flow rate in prostatic hypertrophy, but it does not significantly change symptom scores. 3

DOEs look at the kinds of outcomes that physiologists care about. More relevant are outcomes that patients care about, often called “patient-oriented outcomes.” These are based on “patient-oriented evidence that matters” (POEMs) and look at outcomes such as morbidity, mortality and cost. Thus, when looking at a journal article, DOEs are interesting but of questionable relevance, whereas POEMs are very interesting and very relevant. In the study on the previous page, the outcome is complete resolution of the wart, which is something your patient is interested in.

Number. The number of subjects is crucial to whether accurate statistics can be generated from the data. Too few patients in a research study may not be enough to show that a difference actually exists between the intervention and comparison groups (known as the “power” of a study). Many studies are published with less than 100 subjects, which is usually inadequate to provide reliable statistics. A good rule of thumb is 400 subjects. 4 Fifty-one patients completed the wart study, which is a pretty small number to generate good statistics.

Statistics. The statistics you are interested in are few in number and easy to understand. Since statistics are frequently misused in journal articles, it is worth a few minutes to learn which to believe and which to ignore.

Relative risk reduction. It is not unusual to find a summary statement in a journal article similar to this one from an article titled “Long-Term Effects of Mammography Screening: Updated Overview of the Swedish Randomised Trials”: 5

“There were 511 breast cancer deaths in 1,864,770 women-years in the invited groups and 584 breast cancer deaths in 1,688,440 women-years in the control groups, a significant 21 percent reduction in breast cancer mortality.”

This 21-percent statistic is the relative risk reduction (RRR), which is the percent reduction in the measured outcome between the experimental and control groups. (See “Some important statistics” for more information on calculating the RRR and other statistics.) The RRR is not a good way to compare outcomes. It amplifies small differences and makes insignificant findings appear significant, and it doesn’t reflect the baseline risk of the outcome event. Nevertheless, the RRR is very popular and will be reported in nearly every journal article, perhaps because it makes weak results look good. Think of the RRR as the “reputation reviving ratio” or the “reporter’s reason for ‘riting.” Ignore the RRR. It will mislead you. In our wart treatment example, the RRR would be (85 percent - 60 percent)/60 percent x 100 = 42 percent. The RRR could thus be interpreted as showing that duct tape is 42 percent more effective than cryotherapy in treating warts.

SOME IMPORTANT STATISTICS

Absolute risk reduction (ARR): The difference between the control group’s event rate (CER) and the experimental group’s event rate (EER).

Control event rate (CER): The proportion of patients responding to placebo or other control treatment. For example, if 25 patients are in a control group and the event being studied is observed in 15 of those patients, the control event rate would be 15/25 = 0.60.

Experimental event rate (EER): The proportion of patients responding to the experimental treatment or intervention. For example, if 26 patients are in an experimental group and the event being studied is observed in 22 of those patients, the experimental event rate would be 22/26 = 0.85.

Number needed to treat (NNT): The number of patients that must be treated to prevent one adverse outcome or for one patient to benefit. The NNT is the inverse of the ARR; NNT = 1/ARR.

Relative risk reduction (RRR): The percent reduction in events in the treated group compared to the control group event rate.

When the experimental treatment reduces the risk of a bad event:Example: Beta-blockers to prevent deaths in high-risk patients with recent myocardial infarction:When the experimental treatment increases the probability of a good event:Example: Duct tape to eliminate common warts.
Relative risk reduction (RRR)CER-EER/CER(.66 -. 50)/.66 = .24 or 24 percentEER-CER/CER(.85-.60)/.60 = .42 or 42 percent
Absolute risk reduction (ARR):CER-EER(.66 - .50) = .16 or 16 percentEER-CER.85-.60 = .25 or 25 percent
Number needed to treat (NNT)1/ARR1/.16 = 61/ARR1/.25 = 4

Absolute risk reduction. A better statistic is the absolute risk reduction (ARR), which is the difference in the outcome event rate between the control group and the experimental treated group. Thus, in our wart treatment example, the ARR is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent. Unlike the RRR, the ARR does not amplify small differences but shows the true difference between the experimental and control interventions. Using the ARR, it would be accurate to say that duct tape is 25-percent more effective than cryotherapy in treating warts.

Number needed to treat. The single most clinically useful statistic is the number needed to treat (NNT). The NNT is the number of patients who must be treated to prevent one adverse outcome. To think about it another way, the NNT is the number of patients who must be treated for one patient to benefit. (The rest who were treated obtained no benefit, although they still suffered the risks and costs of treatment.) In our wart therapy article, the NNT would tell us how many patients must be treated with the experimental treatment for one to benefit more than if he or she had been treated with the standard treatment.

Now this is a statistic that physicians and their patients can really appreciate! Furthermore, the NNT is easy to calculate, as it is simply the inverse of the ARR. For our wart treatment study, the NNT is 1/25 percent =1/0.25 = 4, meaning that 4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy.

Wrapped up in this simple little statistic are some very important concepts. The NNT provides you with the likelihood that the test or treatment will benefit any individual patient, an impression of the baseline risk of the adverse event, and a sense of the cost to society. Thus, it gives perspective and hints at the “reasonableness” of a treatment. The value of this statistic has become appreciated in the last five years, and more journal articles are reporting it.

What is a reasonable NNT? In a perfect world, a treatment would have an NNT of 1, meaning that every patient would benefit from the treatment. Real life is not so kind (see “Examples of NNTs” ). Clearly, an NNT of 1 is great and an NNT of 1,000 is terrible. Although it is hard to come up with firm guidelines, for primary therapies I am satisfied with an NNT of 10 or less and very pleased with an NNT less than 5. Our duct tape NNT of 4 is good, particularly since the treatment is cheap, easy and painless.

EXAMPLES OF NNTS

The number needed to treat (NNT) is one of the most useful statistics for physicians and patients. It calculates the number of patients that must be treated to prevent one adverse event or for one patient to benefit. Note that NNTs for preventive interventions will usually be higher than NNTs for treatment interventions. The lower the NNT, the better.

The following examples of NNTs are borrowed from an excellent list available through the Bandolier Web site at http://www.jr2.ox.ac.uk/bandolier/band50/b50-8.html .

Triple antibiotic therapy to eradicate 1.1
Isosorbide dinitrate for prevention of exercise-induced angina5
Short course of antibiotics for otitis media in children7
Statins for secondary prevention of adverse cardiovascular outcomes11
Statins for primary prevention of adverse cardiovascular outcomes35
Finasteride to prevent one operation for benign prostatic hyperplasia39
Misoprostol to prevent any gastrointestinal complication in nonsteroidal anti-inflammatory drug users166

Note that NNTs for preventive interventions (e.g., the use of aspirin to prevent cardiac problems) will usually be higher than NNTs for treatment interventions (e.g., the use of duct tape to cure warts). Prevention groups contain both higher-risk and lower-risk individuals, so they produce bigger denominators, whereas treatment groups only contain diseased patients. Thus, an NNT for prevention of less than 20 might be particularly good.

When discussing a particular therapy, I explain the NNT to my patient. Since this statistical concept is easy to understand, it can help the patient be a more informed partner in therapeutic decisions.

You will soon start to see a similar statistic, the number needed to screen (NNS), which is the number of patients needed to screen for a particular disease for a given duration for one patient to benefit. 6 Although few NNSs have been calculated, they are likely to involve higher numbers, since the screening population consists of patients with and without the disease. For example, in the article on mammography screening mentioned above, the NNS was 961 for 16 years. In other words, you would need to screen 961 women for 16 years to prevent one breast cancer death.

The good news and the bad

Using PP-ICONS to assess the wart study, the problem, the patient/population, the intervention, the comparison and the outcome are all relevant to your patient. The number of subjects is on the small side, making you a little wary, but the intervention is cheap and low-risk. The statistics, particularly the NNT, are reasonable. On balance, this looks like a fair approach, so you call the patient’s mother and discuss it with her.

The PP-ICONS approach is an easy way to screen an article for validity and relevance, and the abstract often contains all of the information you need. Even the statistics can be done quickly in your head. You can apply PP-ICONS when searching for a particular article, when you come across an article in your reading, when data are presented at lectures, when a pharmaceutical representative hands you an article to support his or her pitch, and even when reading news stories describing medical breakthroughs.

Don’t be discouraged if you find that high-quality articles are rare, even in the most prestigious journals. This seems to be changing for the better, although many careers are still being built on questionable research. Nevertheless, screening articles will help you find the truth that is out there and will help you practice the best medicine. And as we become more discerning end-users of research, we might just stimulate improvements in clinical research in the process.

Miser WF. Critical appraisal of the literature. J Amer Board Fam Pract . 1999;12(4):315-333.

Guyatt GH, et al. Users’ guides to the medical literature. How to use an article about therapy or prevention. Are the results of the study valid?. JAMA . 1993;270(21):2598-2601.

Lepor H, et al. The efficacy of terazosin, finasteride or both in benign prostatic hyperplasia. Veterans Affairs Cooperative Studies Benign Prostatic Hyperplasia Study Group. N Engl J Med . 1996;335(8):533-539.

Krejcie RV, Morgan DW. Determining sample size for research activities. Educational and Psychological Measurement . 1970;30:607-610.

Nystrom L, et al. Long-term effects of mammography screening: updated overview of the Swedish randomised trials. Lancet . 2002;359(9310):909-919.

Rembold CM. Number needed to screen: development of a statistic for disease screening. BMJ . 1998;317:307-312.

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Medical literature review: Search or perish

Literature review is a cascading process of searching, reading, analyzing, and summing up of the materials about a specific topic. However, searching the literature is like searching “a needle in a haystack”, and hence has been called “Cinderella”. 1 Therefore, skills and effective pathways of searching the literature are needed to achieve high sensitive and specific results.

Importance of searching the literature:

A good review of previously published work has many advantages. Firstly, it prevents wasteful salami work, and hence saves financial resources. Secondly, it is a pathway of creating new idea from others’ work by filling the research gaps in the previous work and trying to know what is unknown about a specific topic. Steward 1 has summarized the criteria of a good literature review.

Literature search engines: pros and cons:

It is worth noting that the researchers should have a previous knowledge about the different available literature searches such as PubMed, MEDLINE, CINAHL, Google Scholar, and many others. The characteristics of the most literature searches have been previously mentioned 2 , and the comparison between the efficiency and effectiveness of the two most popular literature searches (the PubMed and Google Scholar) have been extensively studied. The question arises which literature search should the authors use to obtain an appropriate results? The answer is the knowledge that the authors must know about the pros and cons of each literature search and the complementary pathways that should be used to retrieve most of the related work about a specific topic. There is an ongoing debate about the accuracy, precision, sensitivity, and specificity of either using the PubMed or a search engine (e.g., Google Scholar) as a major tool of searching the literature. 3 - 7 However, combining the simplicity, speed, and the accessibility of the “grey” literature using the Google Scholar 8 with the strengths of the PubMed is highly recommended and will retrieve highly sensitive and specific results. The “Net Generation” prefers using the Google Scholar rather than the PubMed. However, authors must appreciate the limitations of every pathway they use and to combine different pathways is always better to get an optimal literature results.

Searching the literature: An example:

As searching the literature depends on the clinical question, selection of search terms, framing the questions, or key words, authors should spend time to consider different terms to avoid missing any article, which could be disastrous. Searching terms are the “bait fish” which are used as a bait to capture and retrieve most if not all of the related work about a specific topic.

Example of good terms formatting:

To the best of my knowledge, only two studies have investigated the level of β 3 integrin in the serum of healthy donors. To find the two papers in the “haystack” try the following luring terms, using both Google Scholar and PubMed.

  • Serum β3 vs serum beta3.
  • Plasma B3 vs serum B3.
  • Serum beta3 and healthy vs serum beta3 and disease.

The only term which will retrieve successfully the two papers is “serum beta3 and disease” using both Google Scholar and the PubMed, however, much faster using Google.

Top tips of searching the literature:

Galaxies of tips have been suggested and many are available with videos and illustrations on the internet. Goggling the term “tips for searching the literature” will retrieve about 7.050.000 results. However, a very recent article suggested only four steps, 9 and another recommended 18 steps 10 for an effective literature searching. Having a good plan and enough time for framing the appropriate questions, as mentioned above in the example, will facilitate retrieving of the most if not all related work about a specific topic. One should always prefer combining different search terms and using the strengths of the two pals search engines (PubMed and Google Scholar) to achieve a high sensitive and specific search results. Maximum patience is desired in this stage by the authors to trap all related work, and keep in mind “keep Googling and PubMeding” will keep you on a safe side. Some additional tips for searching the literature are illustrated in Fig.1 .

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Object name is pjms-29-680-g001.jpg

Hints for literature search.

Most wanted articles: the process of weeding out:

After searching and collecting the literature, the authors need to weed out what they have collected and critically evaluate the sensitivity and specificity of the collected materials. This process is a vital to weed out the most wanted and related material about a specific topic. In addition, one can rapidly scan the dimensions of the topic and can find further key words and phrases for the future search. The collected materials can contain peer-reviewed and non-peer-reviewed materials; therefore, care should be taken while analyzing the search results. Further suggestions and recommendations on evaluating the collected literature have been suggested in different studies. 11 - 13

Acknowledge the chaotic or systematic search:

The term “to the best of my knowledge” can be used to describe gently the probability of inadvertently missing of one article about a specific topic. However, missing an article may result either from a chaotic searching strategy, not all medical journals are indexed in the PubMed, inappropriate searching terms and key words, or missing the articles which are published in non-English languages. The junior authors and the “Net Generation” use this term more often in their writing, however, the senior reviewers will find it out very easily. Hence, it is always worthwhile to spend more time in framing and phrasing the sound terms, questions, and key words and to use these terms for capturing all related work about a specific topic and using the right search engines.

Conclusions: Best search leads to best research:

A searching plan is a perquisite step to get high accurate and precise results. The plan should detail all necessary key words and phrases that should be tried by the authors. Evaluation of the collected material is pivotal to assess the sensitivity and the specificity of both the search terms and the search engines used. Keeping in mind the literature review is one step in the chain of publishing the authors’ work, and best searching strategies lead to best research results and hence a worthy publications.

Conflict of interest: None.

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  1. 2. Literature Review

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  4. Using ChatGPT for Research Literature Review (quick demo)

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  6. AI for Medical Literature Analysis: Extracting Insights and Research Trends! Part 1 #ai #aiinindia

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  1. Literature Reviews

    There are a number of reporting guideline available to guide the synthesis and reporting of results in systematic literature reviews. Example: ... Cook, D. A., & West, C. P. (2012). Conducting systematic reviews in medical education: a stepwise approach. Medical Education, 46(10), 943-952. << Previous: Critical Appraisal Resources; Next: What ...

  2. The Literature Review: A Foundation for High-Quality Medical Education

    For example, the resources ... The literature review is a vital part of medical education research and should occur throughout the research process to help researchers design a strong study and effectively communicate study results and importance. To achieve these goals, researchers are advised to plan and execute the literature review ...

  3. Ten Simple Rules for Writing a Literature Review

    Literature reviews are in great demand in most scientific fields. Their need stems from the ever-increasing output of scientific publications .For example, compared to 1991, in 2008 three, eight, and forty times more papers were indexed in Web of Science on malaria, obesity, and biodiversity, respectively .Given such mountains of papers, scientists cannot be expected to examine in detail every ...

  4. How to 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.

  5. Writing an effective literature review

    Mapping the gap. The purpose of the literature review section of a manuscript is not to report what is known about your topic. The purpose is to identify what remains unknown—what academic writing scholar Janet Giltrow has called the 'knowledge deficit'—thus establishing the need for your research study [].In an earlier Writer's Craft instalment, the Problem-Gap-Hook heuristic was ...

  6. How to Write an Evidence-Based Clinical Review Article

    Traditional clinical review articles, also known as updates, differ from systematic reviews and meta-analyses. Updates selectively review the medical literature while discussing a topic broadly ...

  7. Writing an Effective Literature Review

    A literature review can be an informative, critical, and useful synthesis of a particular topic. It can identify what is known (and unknown) in the subject area, identify areas of controversy or debate, and help formulate questions that need further research. There are several commonly used formats for literature reviews, including systematic reviews conducted as primary research projects ...

  8. Writing a literature review

    When writing a literature review it is important to start with a brief introduction, followed by the text broken up into subsections and conclude with a summary to bring everything together. A summary table including title, author, publication date and key findings is a useful feature to present in your review (see Table 1 for an example).

  9. PDF Doing a Literature Review in Health

    Doing a Literature Review in Health33 This chapter describes how to undertake a rigorous and thorough review of the literature and is divided into three sections. The first section examines the two main types of review: the narrative and the systematic review. The second section describes some techniques for undertaking a comprehensive search,

  10. How to Conduct a Literature Review (Health Sciences and Beyond)

    The other pages in this guide will cover some basic steps to consider when conducting a traditional health sciences literature review. See below for a quick look at some of the more popular types of literature reviews. For additional information on a variety of review methods, the following article provides an excellent overview. Grant MJ, Booth A.

  11. Writing a Literature Review

    Run a few sample database searches to make sure your research question is not too broad or too narrow. If possible, discuss your topic with your professor. 2. Determine the scope of your review. The scope of your review will be determined by your professor during your program. Check your assignment requirements for parameters for the Literature ...

  12. Literature Reviews

    Literature Review. Generic term: published materials that provide examination of recent or current literature. Can cover wide range of subjects at various levels of completeness and comprehensiveness. May include research findings. May or may not include comprehensive searching. May or may not include quality assessment.

  13. Performing a literature review

    Literature reviews are most commonly performed to help answer a particular question. While you are at medical school, there will usually be some choice regarding the area you are going to review. Once you have identified a subject area for review, the next step is to formulate a specific research question. This is arguably the most important ...

  14. Further reading & examples

    Examples of literature reviews; Articles on literature reviews; Family needs and involvement in the intensive care unit: a literature review ... Brown, D. (2004). A literature review exploring how healthcare professionals contribute to the assessment and control of postoperative pain in older people. Journal of Clinical Nursing, 13(6b), 74-90 ...

  15. PDF Example of Literature Review

    Example of Literature Review The following was extracted from ... Laboratory study with medical students and physicians showed significant time savings and increased accuracy Randomized controlled trial showed that the NUCRSS improved process level (patient's length of stay and increased the amount of laboratory tests ordered) outcomes and ...

  16. Writing in the Health Sciences: Research and Lit Reviews

    PubMed - The premier medical database for review articles in medicine, nursing, healthcare, other related biomedical disciplines. PubMed contains over 20 million citations and can be navigated through multiple database capabilities and searching strategies. CINAHL Ultimate - Offers comprehensive coverage of health science literature. CINAHL is particularly useful for those researching the ...

  17. 15 Literature Review Examples (2024)

    A narrative review on burnout experienced by medical students and residents (Dyrbye & Shanafelt, 2015) - read here; 2. Systematic Review Examples. This type of literature review is more structured and rigorous than a narrative review. It involves a detailed and comprehensive plan and search strategy derived from a set of specified research ...

  18. LibGuides: Writing a Literature Review: Examples & Tutorials

    Sample Literature Review-Here is a sample literature review written by a librarian at American University Library.. Deshmukh, Marion F. "The Visual Arts and Cultural Migration in the 1930s and 1940s: A Literature Review." Central European History (Cambridge University Press / UK) 41.4 (2008): 569-604. Dunjó, Jordi, et al. "Hazard and Operability (HAZOP) Analysis.

  19. Chapter 9 Methods for Literature Reviews

    Literature reviews play a critical role in scholarship because science remains, first and foremost, a cumulative endeavour (vom Brocke et al., 2009). As in any academic discipline, rigorous knowledge syntheses are becoming indispensable in keeping up with an exponentially growing eHealth literature, assisting practitioners, academics, and graduate students in finding, evaluating, and ...

  20. A Simple Method for Evaluating the Clinical Literature

    Reading the abstract is often sufficient when evaluating an article using the PP-ICONS approach. The most relevant studies will involve outcomes that matter to patients (e.g., morbidity, mortality ...

  21. Literature Review

    Literature Review: A literature review gives an overview of the field of inquiry: what has already been said on the topic, who the key writers are, what the prevailing theories and hypotheses are, what questions are being asked, and what methodologies and methods are appropriate and useful.. A critical literature review shows how prevailing ideas fit into your own thesis, and how your thesis ...

  22. Sample Literature Reviews

    Steps for Conducting a Lit Review; Finding "The Literature" Organizing/Writing; APA Style This link opens in a new window; Chicago: Notes Bibliography This link opens in a new window; MLA Style This link opens in a new window; Sample Literature Reviews. Sample Lit Reviews from Communication Arts; Have an exemplary literature review? Get Help!

  23. Medical literature review: Search or perish

    Abstract. Literature review is a cascading process of searching, reading, analyzing, and summing up of the materials about a specific topic. However, searching the literature is like searching "a needle in a haystack", and hence has been called "Cinderella". 1 Therefore, skills and effective pathways of searching the literature are ...