Scoping reviews

Scoping reviews aim to map the key concepts within a research area and the types of evidence that is available (Arksey and O'Malley, 2005). Wheras systematic reviews focus on a clearly defined question, and usually identify the most relevant study types for inclusion in advance, scoping reviews are broader in their remit and may include a range of different types of study within the review.

Search strategies for scoping reviews are determined by the time available and the specific scope of the topic area. They do not usually involve any type of quality assessment (wheras studies within systematic reviews are critically appraised for quality and risk of bias) (Grant and Booth, 2009).

You may wish to conduct a scoping review for the following reasons:

• To indicate whether a full systematic review would be feasible or beneficial
• To identify gaps in knowledge on a specific topic
• To map the existing literature on a topic
• To better understand the types of research carried out within a topic
• To clarify concepts, definitions or terminology within a specific topic area

While many of the approaches to forming a comprehensive and systematic search strategy are similar across both types of review, the two methods have different purposes and aims.

While systematic reviews aim to identify and synethesise all of the relevant evidence relevant to answering a specific question in order to make recommendations for policy or practice, the aim of a scoping review is to map the available evidence on a topic, without following a process for assessing the quality of the studies included.

Like systematic review searches, scoping review search strategies aim to be systematic, transparent and reproducible. Scoping reviews however are not usually a research output in their own right due to their limitations. These include:

•  A lack of quality assessment 
• Limitations in rigour and duration

(Grant and Booth, 2009)