Scoping reviews are a preliminary assessment of the potential size and scope of available research literature. They aim to identify the nature and extent of research evidence, usually including ongoing research. Scoping reviews are often used to categorize or group existing literature in terms of its nature, features, and volume.
Note: Often a scoping review is confused with a mapping review. They are two different review types. Scoping reviews are more topic based and mapping reviews are more question based.
Scoping Reviews may be best designed for:
When the literature has not been comprehensively reviewed yet, or the topic is broader than what a systematic review would cover.
(Source: Peters M, Godfrey C, Khalil H, et al, 2015)
Limitations
Timeframe: 12+ months, (same amount of time as a systematic review or longer)
*Varies beyond the type of review. Depends on many factors such as but not limited to: resources available, the quantity and quality of the literature, and the expertise or experience of reviewers" (Grant et al. 2009)
Question: Answers broader and topic focused questions beyond those relating to the effectiveness of treatments or interventions. A priori review protocol is recommended.
Sources and searches: Comprehensive search-may be limited by time/scope restraints, still aims to be thorough and repeatable of all literature. May involve multiple structured searches rather than a single structured search. This will produce more results than a systematic review. Must include a modified PRISMA flow diagram.
Selection: Based on inclusion/exclusion criteria, due to the iterative nature of a scoping review some changes may be necessary. May require more time spent screening articles due to the larger volume of results from broader questions.
Appraisal: Critical appraisal (optional), Risk of Bias assessment (optional) is not applicable for scoping reviews.
Synthesis: Tabular with some narrative. The extraction of data for a scoping review may include a charting table or form but a formal synthesis of findings from individual studies and the generation of a 'summary of findings' (SOF) table is not required. Results may include a logical diagram or table or any descriptive form that aligns with the scope and objectives of the review. May incorporate a numerical summary and qualitative thematic analysis.
(Sources: MDJ Peters et al., 2015 & Levac et al., 2010)