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Systematic Reviews: What is a Systematic Review?

Provides an overview of the Systematic Review process and offers information on standards and best practices.

 systematic review graphic with cog wheels and light bulb

Definition and Elements

A systematic review is a comprehensive literature search that tries to answer a focused research question using existing research as evidence. 

Elements of a Systemic Review: 

  1. Research team: including two independent screeners, a tie-breaker, librarian, and statistician
  2. Focused research question, including a measurable outcome
  3. Written and registered protocol: PROSPERO
  4. Inclusion/exclusion criteria
  5. Comprehensive literature searches of multiple databases: often performed by a librarian
  6. Screening and study selection: two independent screeners, conflicts resolved by third reviewer
  7. Quality assessment: transparent assessment using validated tools
  8. Reporting guidelines: following PRISMA checklist
  9. Time: systematic reviews can take at least 12 months to complete

Types of Reviews

Although systematic reviews may be the best known review type, there are a variety of different types of literature reviews that vary in terms of scope, comprehensiveness, time constraints, and types of studies included.

descriptions of types of reviews

Grant, M.J., & Booth, A. (2009). A typology of reviews: An analysis of 14 review types and associated methodologies. Health Information & Libraries Journal, 26, 91–108.
Higgins JPT, Green S (editors).Box 2.3.b: Timeline for a Cochrane review. Cochrane Handbook for Systematic Reviews of Interventions. Version 5.1.0 [updated March 2011]. The Cochrane Collaboration. Available from Accessed February 16, 2018.


Some content in this guide has been copied, with permission, from : What is a Systematic Review? - Systematic Reviews - Guides at Medical University of South Carolina (

Many thanks to the staff at MUSC Libraries for their generosity in sharing this content.