Literature reviews & systematic reviews

There are many types of reviews available to researchers and it is important to select the most appropriate method.

Which review?

Your decision will be based on the type of research question, the intended purpose and audience, the resources, skills and time you have available.

Common review types include:

Systematic review 

Designed to answer precisely defined questions; aims to collate all empiral evidence. Uses explicit methods to minimise bias and provide more reliable findings to inform clinical decisions. See more

Scoping review

Addresses broader, exploratory research questions; can map key concepts in research areas, and clarify working definitions or conceptual boundaries of a topic

Rapid review

Assesses what is already known about a policy issue; frequently used for organisational reports, government reports, or health technology assessments

Umbrella review (or Review of reviews)

Synthesises the evidence from a cluster of existing systematic reviews to provide a current "state of knowledge"

Integrative review

Provides a thorough appraisal, interpretation and synthesis of empirical and theoretical literature

Further reading:

A typology of reviews: an analysis of 14 review types and associated methodologies

EVIDENT Guidance for reviewing the evidence: a compendium of methodological literature and websites

Systematic review or literature review?

Narrative reviews do not usually require systematic search protocols or explicit criteria for selecting and appraising evidence. Instead, they rely on experts to gather evidence and synthesise findings. 

Systematic Reviews
Narrative Reviews
Investigate a clearly defined topic or question. Intended to provide an overview of an area.
Literature is gathered using explicit search protocols. Explicit, systematic literature search protocol not used.
Studies selected for the review using a protocol that specifies inclusion, exclusion criteria. Studies used to support the reviewers' recommendations are not selected according to an explicit, predetermined protocol.
Data from primary study may be synthesized in a meta-analysis. Evidence "grades" may be applied to individual studies. May use a level of evidence rating system to "grade" the quality and strength of individual studies.
When evidence is lacking, the authors usually recommend further research. When evidence is lacking, the authors make recommendations based on their opinions and experience. Recommendations may be "graded" based on the consistency and strength of the underlying evidence.

Adapted from The Gustave L. and Janet W. Levy Library guide