Nursing

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:

1. Literature review steps
2. Strategies for organizing the information for your review
3. Literature reviews sections
4. In-depth resources to assist in writing a literature review
5. Templates to start your review
6. Literature review examples

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.

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
• columns might contain:
  • theme
  • reference
  • article summary, analysis, or results
  • thoughts, reflections, or issues
• each reference gets its own row
• example

2. Mapping

• uses a diagram to present core ideas and concepts 
  • 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
• example

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
• columns may contain such information as:
  • reference
  • purpose of study
  • methodology (study population, data collection tool)
  • findings
• example

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

• 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):

• Introduction:
  • 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
• Methodology:
  • Narrative Reviews: tmay not have an explanation of methods.
  • However, if a Methods Section is part of your rubric:
    • 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
• Results:
  • review the purpose and answer the research question
  • findings can be organized in several ways: 
    • 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
• Discussion:
  • 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
• Conclusion:
  • 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
• References:
  • 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

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
• Systematic review design and methodology:
  • 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

These sources have been used in developing this guide.

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

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

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