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
According to Munn et al. (2018), scoping reviews should be done:
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
Important: Before embarking on a scoping review, make sure that 1) a recent review on the same topic has not already been published, and that 2) a review protocol has not already been registered for the same topic.
To check for published and registered (i.e. forthcoming) scoping reviews, search databases such as Ovid MEDLINE, CINAHL, and even Google Scholar. Also try searching in the following journals for scoping review protocols before you get started:
Consult the chart below for some other differences between systematic reviews and scoping reviews.
|Scoping Review||Systematic Review|
|Purpose/Aim||Provides a narrative or descriptive account of available information||Provides empirical evidence that meets pre-specified criteria|
|Protocol Required||Developed a priori and post hoc||Developed a priori|
|Research Question||Broadly defined||Highly focused|
|Comprehensive Search||Explicit and transparent||Explicit and transparent|
|Inclusion/Exclusion Criteria||Developed at protocol stage||Developed at protocol stage|
|Study Selection||All study types||Defined study types; need to meet quality standards|
|Critical Appraisal||No critical appraisal of included studies||Quality and risk of bias assessment included|
|Statistical Analysis||"Charts" data according to key issues, themes, etc.||Synthesizes and aggregates findings; often with a meta-analysis|
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.