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Systematic and Literature Reviews

What is a Systematic Review?

A systematic review attempts to collate all empirical evidence that fits pre-specified eligibility criteria in order to answer a specific research question. The key characteristics of a systematic review are: a clearly defined question with inclusion & exclusion criteria; rigorous & systematic search of the literature; critical appraisal of included studies; data extraction and management; analysis & interpretation of results; and report for publication.

Summary of Types of LIterature Reviews

Evidence maps and systematic maps

  • Systematically and transparently collects and categorizes existing evidence on a broad question of policy or management importance.

  • May critically evaluate existing evidence, but does not attempt to synthesize the results in the way a systematic review would. (see EE Journal and CIFOR)

Literature (Narrative) Review

  • A broad term referring to reviews with a wide scope and non-standardized methodology. 

  • Search strategies, comprehensiveness, and time range covered will vary and do not follow an established protocol.

Meta-analysis

  • Statistical technique for combining the findings from disparate quantitative studies.

  • Uses statistical methods to objectively evaluate, synthesize, and summarize results.

  • May be conducted independently or as part of a systematic review.

Rapid Review

Scoping Review

  • Addresses a broader research question or set of questions

  • Often conducted in preparation for conducting a systematic review

  • Seeks to identify research gaps and opportunities for evidence synthesis

  • See Peterson et. al. (2016) for methodological guidance.

Umbrella Review

  • Reviews other systematic reviews on a topic. 

  • Often defines a broader question than is typical of a traditional systematic review.

  • This type of review is most useful when there are competing interventions to consider.

Traditional vs Systematic Reviews