A scoping review "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. 2014, pp. 1292-94. Like other types of evidence synthesis, scoping reviews follow certain standards and guidelines but in this case, the review attempts to assess the size and scope of the available literature.
Scoping reviews can be conducted (Munn et. al., 2018):
to identify the types of available evidence in a given field
to clarify key concepts and/or definitions in the literature
to examine how research is conducted on a given topic
to identify key characteristics or factors related to a concept
to identify and analyze gaps in the knowledge base
as a precursor to a systematic review
A scoping review differs from a systematic review in several key ways (table from RMIT University):
| Scoping review | Systematic review | |
|---|---|---|
| Purpose | Provides literature overview, identifies research gaps, and defines boundaries. | Synthesises research to guide clinical decisions. |
| Focus | Addresses broad questions without critical appraisal. | Focuses on a specific question with critical appraisal. |
| Outcome | Gives a descriptive overview without decision statements or meta-analysis. | Produces evidence, may include meta-analysis, to guide practice. |
| Scope | Includes various study designs, not limited to interventions. | Focuses on specific interventions, collating evidence from fewer studies. |
If you are in doubt about which type of review suits your research question, ask a librarian.
The Ontario Tech Library has compiled a list of common misconceptions about scoping reviews:
Misconception #1: Scoping Reviews can be completed quicker than Systematic Reviews
Truth: Not always. In a study by Khalil et al (2020), 42% participants reported that the scoping review they had been involved with had taken between 6 and 12 months, and 32% of participants spent over a year completing their reviews.
Misconception #2: Scoping Reviews are easier to complete than Systematic Reviews
Truth: Scoping Reviews are "systematic-like" and require a rigorous approach. The comprehensive search may be limited by time/scope restraints, but still aims to be thorough and to be transparent and replicable in its methods.
Misconception #3: Scoping Reviews have fewer articles to screen than Systematic Reviews
Due to the broader nature of this reviews, you may actually have more articles to screen than for a systematic review (i.e. 3000-4000 results). The teams for scoping reviews are often bigger than those for systematic reviews partially due to this reason. Like with a systematic review, results must be screened and appraised by a minimum of two reviewers, ideally with a third available to settle any disagreements.
***Based on the JBI framework enhancements proposed by Peters et al (2015, 2017, 2020)
