Research and Course Guides: BIOL 474: Biology of Global Health: Types of Literature Reviews

Knowledge Syntheses - Differences and Similarities

The following table, developed by the University of Toronto Libraries, displays the similarities and differences between the most common types of reviews. This table was adapted from a variety of sources (Booth, 2016; Grant and Booth, 2009; Higgins & Green, 2011; Pham et al., 2014; and Tricco et al., 2015)

Knowledge synthesis	A priori protocol required?	Protocol registration required?	Comprehensive search?	Duplicate screening & data extraction?	Critical appraisal?	Statistical analysis?	Time
Systematic Review	YES, often published	PROSPERO, JBI, OSF	YES	YES	YES	YES	1+ yr
Meta Analysis	YES, often published	PROSPERO, JBI, OSF	YES	YES	YES	YES	1+ yr
Scoping Review	YES	JBI, OSF, Research Registry & other registries	YES	YES	NO	NO, charted evidence	~ 1 yr
Rapid Review	YES, often not published	OSF, Research Registry, & other registries	NO, varied # of databases, dates and other limits	Varied	NO, but recommended	NO, varied analysis methods	~1 - 6 mo
Realist Review	YES, some published	OSF, Research Registry, & other registries	YES	YES	NO	NO	1+ yr
Overview of reviews	YES, often published	PROSPERO, OSF, & other registries	YES, only reviews included	YES	YES	YES	~ 1 yr
Mapping Review	Encouraged	OSF, Research Registry, & other registries	YES	Varied	NO	NO	1+ yr
Narrative Review	NO	Not necessary	Varied, not necessary	Varied, not necessary	NO	NO	6 mo - 1 yr

Spotlight on Scoping Reviews

A scoping review is a literature review which maps the extent, range, or nature of research on a topic or question. It uses explicit, reproducible methods to identify all studies meeting pre-specified eligibility criteria to determine whether a systematic review is necessary, summarize available evidence, identify gaps in research, and plan for future research.

You should conduct a scoping review if you want:

To examine the extent, range and nature of research activity
To determine the value of undertaking a full systematic review
To summarize and disseminate research findings
To identify research gaps in the existing literature¹

Grey Literature

Grey literature is any material published outside of book and journal publishing. This includes most webpages, government documents, theses, corporate documents, reports, conference proceedings, online handbooks and manuals, and much more. Systematic and scoping reviews often include information from clinical trial registers, theses, and conference abstracts. Health technology assessments often include information from other HTA's or systematic reviews, economic reports, government regulatory information, clinical practice guidelines, etc.