Systematic Reviews

A systematic review attempts to collate all empirical evidence that fits pre-specified eligibility criteria in order to answer a specific research question.  It uses explicit, systematic methods that are selected with a view to minimizing bias, thus providing more reliable findings from which conclusions can be drawn and decisions made. The key characteristics of a systematic review are: 

• a clearly stated set of objectives with pre-defined eligibility criteria for studies;
• an explicit, reproducible methodology;
• a systematic search that attempts to identify all studies that would meet the eligibility criteria;
• an assessment of the validity of the findings of the included studies, for example through the assessment of risk of bias; and
• a systematic presentation, and synthesis, of the characteristics and findings of the included studies.

(Chapter 1.2.2, Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from www.cochrane-handbook.org.)

What Are Systematic Reviews: a video from the Cochrane Consumers and Communication Group.

A meta-analysis uses statistical methods to combine information from a number of separate but similar studies and derive conclusions on that subject. 

A literature review intends to provide an overview of a subject.  It does not include a systematic search of the literature or a description of the methods used in the review and is sometimes based on author experience.  These reviews may be subject to bias. 

Kysh, Lynn (2013): Difference between a systematic review and a literature review. [figshare]. Available at: http://dx.doi.org/10.6084/m9.figshare.766364

Rapid review -  A rapid review is like an accelerated systematic review.  It may take 2-4 months to complete. While it assesses the evidence, it lacks the rigor of a full systematic review.

Definitions for various types of reviews are available from Grant MJ, Booth A. A typology of reviews: an analysis of 14 review types and associated methodologies. Health Info Libr J. 2009 Jun;26(2):91-108. doi: 10.1111/j.1471-1842.2009.00848.x. Review. PubMed PMID: 19490148