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Systematic Reviews

What is a Systematic Review?

A systematic review attempts to collate all the empirical evidence that fits pre-specified eligibility criteria in order to answer a specific research question.  

Key Points:

  • Systematic reviews address a need for health decision makers to be able to access high quality, relevant, accessible and up-to-date information.
  • Systematic reviews aim to minimize bias through the use of pre-specified research questions and methods that are documented in protocols, and by basing their findings on reliable research.
  • Systematic reviews should be conducted by a team that includes domain expertise and methodological expertise, who are free of potential conflicts of interest.
  • People who might make - or be affected by - decisions around the use of interventions should be involved in important decisions about the review.
  • Good data management, project management and quality assurance mechanisms are essential for the completion of a successful systematic review.

Lasserson TJ, Thomas J, Higgins JPT. Chapter 1: Starting a review. In: Higgins JPT, Thomas J, Chandler J, Cumpston M, Li T, Page MJ, Welch VA (editors). Cochrane Handbook for Systematic Reviews of Interventions version 6.0 (updated July 2019). Cochrane, 2019. Available from

Review Types

Types of Reviews:

  • Critical Review
  • Literature Review
  • Mapping Review/Systematic Map
  • Meta-Analysis
  • Mixed Studies Review/Mixed Methods Review
  • Overview
  • Qualitative Systematic Review/Qualitative Evidence Syntheses
  • Rapid Review
  • Scoping Review
  • State of the Art Review
  • Systematic Review
  • Systematic Search and Review
  • Systematized Review
  • Umbrella Review

Introduction Video

What does it take to do a systematic review?

Time: The average systematic review can take 18 months.

A Team: A systematic review can't be done alone! Your team should include a subject expert to clarify issues related to the topic; a librarian to identify appropriate databases and develop comprehensive search strategies; reviewers (min. of 2) to screen abstracts and read the full-text; a statistician to assist with data analysis; and a project leader to coordinate and write the final report.

A Clearly Defined Question: Define your research question using the PICO or PICOT format.

     P = Patient, Population, and/or Problem

      I = Intervention

     C = Comparison (not always applicable)

     O = Outcome

     T = Time and/or Type of Study

Comprehensive Literature Searches: Work with a librarian to identity appropriate databases to search and to develop the search strategy.

Citation Management: Use a citation management program to help manage citations retrieved from the literature search.

Standards: Institute of Medicine Standards for Systematic Reviews