Systematic, scoping, and rapid reviews: An overview

This guide was created to give researchers an overview of three common types of evidence synthesis: systematic reviews, scoping reviews, and rapid reviews.

What is evidence synthesis?

Evidence synthesis is "the contextualization and integration of research findings of individual research studies within the larger body of knowledge on the topic. A synthesis must be reproducible and transparent in its methods, using quantitative and/or qualitative methods" (CIHR). Systematic reviews, scoping reviews, and rapid reviews are all forms of evidence synthesis.

What review is right for you?

The Right Review tool might help guide your choice of an evidence synthesis method.

You can get a sense of the wide array of review types on our Literature Reviews for Graduate Students guide.

Below, you'll find a brief comparison of three common types of evidence synthesis: systematic reviews, scoping reviews, and rapid reviews. 

Systematic review
A comprehensive review done by a research team to answer a focused research question
Scoping review
A review addressing an exploratory research question that maps the scope of the evidence, as well as gaps
Rapid review
A review that aims to be rigorous, but has time and/or resource constraints

 

Systematic review

"A systematic review attempts to identify, appraise and synthesize all the empirical evidence that meets pre-specified eligibility criteria to answer a given research question. Researchers conducting systematic reviews use explicit methods aimed at minimizing bias in order to produce more reliable findings that can be used to inform decision making." (Cochrane)

Scoping review

"A scoping review or scoping study is a form of knowledge synthesis that addresses an exploratory research question aimed at mapping key concepts, types of evidence, and gaps in research related to a defined area or field by systematically searching, selecting, and synthesizing existing knowledge" (Colquhoun et al.)

Rapid review

"Rapid reviews are a form of knowledge synthesis in which components of the systematic review process are simplified or omitted to produce information in a timely manner" (Tricco et al.)

 When to use a systematic review

The aim is to address a focused research question with narrow parameters.

 When to use a scoping review

The aim is to summarize "a range of evidence in order to convey the breadth and depth of a field." (Levac, Colquhoun, & O'Brien) 

 When to use a rapid review

The aim is to conduct a rigorous review with limited time and/or resources.

 Time needed for systematic reviews 

9 to 18 months

  Time: scoping reviews

12+ months

  Time: rapid reviews

1 to 6 months

 Reporting guidelines for systematic reviews

PRISMA 

  Reporting guidelines: scoping reviews

PRISMA-ScR

  Reporting guidelines: rapid reviews

PRISMA-RR (under development since 2018); one possibility is to adapt PRISMA guidelines to the constraints of your project

 
 

  Frameworks/ guidance for systematic reviews

 Frameworks/ guidance: scoping reviews

  Frameworks/ guidance: rapid reviews

 Search strategy for systematic reviews

Comprehensive searches across a range of resources with explicit strategies; typically includes grey literature

  Search strategy: scoping reviews 

Comprehensive searches across a range of resources with explicit strategies; typically includes grey literature

  Search strategy: rapid reviews

As comprehensive as time and/or resource constraints permit  

 Considerations for systematic reviews

Requires at least three team members, including expertise in the research area, systematic review methods, statistical analysis, and information retrieval; requires a focused question; involves critical appraisal.

  Considerations: scoping reviews 

Requires at least three team members, including expertise in the research area, scoping review methods, and information retrieval; requires an exploratory question; involves no critical appraisal.

  Considerations: rapid reviews

Can be done by an individual researcher or a research team; due to time and/or resource constraints, rapid reviews are less comprehensive and more prone to bias than systematic and scoping reviews; should provide explanations for shortcuts and subsequent limitations.

This page was adapted from the What's in a Name? comparison chart created by Library Services, Unity Health Toronto. Creative Commons BY-NC-SA 4.0.