In scoping reviews, the data extraction process may be referred to as “data charting”. This process provides the reader with a logical and descriptive summary of the results that aligns with the objective/s and question/s of the scoping review.
A draft charting table or form should be developed and piloted at the protocol stage to record the key information of the source, such as author, reference, and results or findings relevant to the review question/s. This may be further refined at the review stage and the charting table updated accordingly. Some key information that reviewers might choose to chart are:
- Year of publication
- Origin/country of origin (where the source was published or conducted)
- Population and sample size within the source of evidence (if applicable)
- Methodology / methods
- Intervention type, comparator and details of these (e.g. duration of the intervention) (if applicable). Duration of the intervention (if applicable)
- Outcomes and details of these (e.g. how measured) (if applicable)
- Key findings that relate to the scoping review question/s.
A template data extraction instrument for source details, characteristics and results extraction is provided in Appendix 11.1 of this chapter, which can be adapted by reviewers to use in their own scoping review protocols and reviews with citation to the JBI methodology guidance for scoping reviews.
For ease of reference and tracking, it is suggested that reviewers keep careful records to identify each source. As reviewers chart each source, it may become apparent that additional unforeseen data can be usefully charted. Charting the results can therefore be an iterative process whereby the charting table is continually updated. It is suggested that the review team become familiar with the source results and trial the extraction form on two or three sources to ensure all relevant results are extracted. This pilot step should be done by at least two members of the review team. This approach is favored by other authors on the conduct of scoping reviews (Arksey & O’Malley 2005; Armstrong et al. 2011; Valaitis et al. 2012). If this approach is not feasible, other approaches (such as one reviewer extracting and another verifying the data) can be considered. The most important thing is authors are transparent and clear in their methods regarding what and how they have extracted data. Once again, pilot testing is recommended.