A 'scoping review' is designed to scope the existing literature; that is, to characterize the amount of research/evidence on a topic. This initial evaluation helps determine whether a systematic review is warranted and feasible. If deemed feasible, the scoping review can help refine the search question/topic and methodology
Why Conduct a Scoping Review?
A scoping review is important for justifying the large investment of the time and resources needed to conduct a systematic review. The scoping review helps to ascertain the availability of relevant literature, avoid duplication of effort (i.e., duplicate pre-existing systematic reviews) and define the guiding question and methodology. For example, if the body of literature is too small or of poor quality, it will be difficult to draw meaningful conclusions from a systematic review. Conversely, in well-developed topic areas, other reviews may have been recently conducted. In either case, the time and cost of a systematic review may be difficult to justify.
When Should a Scoping Review Be Conducted?
A scoping review should be undertaken prior to conduct of a systematic review. Scoping reviews explore the extent of the literature in a particular domain without describing findings in detail. As scoping reviews precede systematic reviews, they do not typically include methodological assessment of the studies. This limits data synthesis and interpretation but allows the scoping review to be conducted more rapidly than a full systematic review.
Who Should Perform a Scoping Review?
This scoping review should ideally be conducted by an individual with expertise in the topic area. Persons with knowledge in the topic area are likely to be familiar with search terms and/or strategies to identify relevant literature.
Overview of the process for a scoping review
- Refine Search Topic or Question
- Review the assigned topic or question. Topics/questions are likely to be those in which there exist confusion, debate or controversy. If necessary, recommend modifications to the topic/question to ensure a feasible and relevant systematic review.
- Identify Relevant Studies
- Conduct an initial search of the literature. Searches should ideally be conducted using an appropriate medical literature database (e.g., Medline or CINAHL). It is recognized that a scoping review search will likely in volve fewer sources than a systematic review search.
- Tabulate the Data
- Create a table listing relevant citations. Include data that helps characterize the literature (e.g., number of patients, type of interventions, outcome measures used). This helps identify commonalities, themes and gaps in the literature.
- Summarize and Report Results
- Author a narrative summary of the scoping review results and recommendations. Indicate if previous reviews have been conducted (and if so, when) and if there is a sufficient volume of literature available to warrant a systematic review.