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Prevention & Community Health: Literature Review

Research Guide for the GWSPH Department of Prevention and Community Health

Good Place to Start: Citation Databases

Interdisciplinary Citation Databases:

A good place to start your research is to search a research citation database to view the scope of literature available on your topic.

Begin your research with a "seed article" - an article that strongly supports your research topic.  Then use a citation database to follow the studies published by finding articles which have cited that article, either because they support it or because they disagree with it.

Snowballing is the process where researchers will begin with a select number of articles they have identified relevant/strongly supports their topic and then search each articles' references reviewing the studies cited to determine if they are relevant to your research.

BONUS POINTS: This process also helps identify key highly cited authors within a topic to help establish the "experts" in the field.


Begin by constructing a focused research question to help you then convert it into an effective search strategy.

  • Identify keywords or synonyms
  • Type of study/resources
  • Which database(s) to search

Web Resources

What is a literature review?

A literature review is a comprehensive and up-to-date overview of published information on a subject area. Conducting a literature review demands a careful examination of a body of literature that has been published that helps answer your research question (See PICO). Literature reviewed includes scholarly journals, scholarly books, authoritative databases, primary sources and grey literature.

A literature review attempts to answer the following:

  • What is known about the subject?
  • What is the chronology of knowledge about my subject?
  • Are there any gaps in the literature?
  • Is there a consensus/debate on issues?


  1. Create a clear research question/statement
  2. Define the scope of the review include limitations
    (i.e. gender, age, location, nationality...)
  3. Search existing literature including classic works on your topic and grey literature
  4. Evaluate results and the evidence
    (Avoid discounting information that contradicts your research)
  5. Track and organize references

What is PICO?

The PICO model can help you formulate a good clinical question. Sometimes it's referred to as PICO-T, containing an optional 5th factor. 

P - Patient, Population, or Problem

What are the most important characteristics of the patient?

How would you describe a group of patients similar to yours?

I - Intervention, Exposure, Prognostic Factor

What main intervention, prognostic factor, or exposure are you considering?

What do you want to do for the patient (prescribe a drug, order a test, etc.)?

C - Comparison What is the main alternative to compare with the intervention?
O - Outcome What do you hope to accomplish, measure, improve, or affect?
T - Time Factor, Type of Study (optional)

How would you categorize this question?

What would be the best study design to answer this question?

Seminal Works: Search Key Indexing/Citation Databases

TIP – How to Locate Seminal Works

  • DO NOT: Limit by date range or you might overlook the seminal works
  • DO: Look at highly cited references (Seminal articles are frequently referred to “cited” in the research)
  • DO: Search citation databases like Scopus, Web of Science and Google Scholar

Search Example

Literature Review: Research Question Example
  How effective is the use of text messaging to promote awareness of HIV prevention to teens and young adults? PICO:
  How effective is the use of text messaging to promote awareness of HIV prevention to teens and young adults?
  'Text messaging', 'HIV prevention' and 'teens and young adults' are the key concepts.
  Population: Age 16-25 in the United States
  Intervention: Text Messaging HIV Prevention Campaigns
  Comparison: HIV preventoin Campaigns with/without texting messaging
  Outcome: Text messaging HIV prevention campaigns decrease HIV risk behavior Literature Review: Search Strategy Logic
  How to Broaden Or Narrow Your Search:
  AND: combines, narrows
  OR: synonyms, broadens
  NOT: eliminates, narrows
  Text Messaging OR Short Message Service
  HIV OR Human Immunodeficiency Virus Infection
  Prevention OR Program Evaluation
  Young Adult OR Adolescent OR Teenager
  Adults OR Children