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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

Systematic Reviews

Also Called: Comprehensive Review, Review of the Evidence

Purpose: A research method that uses explicit and reproducible methods to systematically search, appraise, and synthesis research evidence. (A study of studies)

Research Question: Clearly defined and focused. A good method to define your research question is 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

Team Size: 3 or more. 

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.

Time to Complete: 12-18+ months

Advantages: Considered the gold standard of evidence synthesis. Applying statistical techniques to the synthesized data can produce a meta-analysis.
Limitations: It requires an extensive amount of time and a team.

Methodology: Systematic and comprehensive search in multiple databases, clear and reproducible descriptive methods. It is recommended to work with a librarian to identify appropriate databases to search and to develop the search strategy.

Standards: Institute of Medicine Standards for Systematic Reviews

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