9.2.10 Data summary

The aim of the JBI Umbrella review is to present a summary of existing research syntheses relevant to a particular topic or question and not any further “meta-analysis” of the results of these publications. To this end, the results of all included studies should be presented to the reader to allow for a ready and easily interpretable overview of the findings.

In the Umbrella Review protocol the means by which the results of the reviews will be presented should be described in as much as detail as possible. Tabular presentation of findings is recommended when overall effect estimates extracted from systematic reviews or other similar numerical data are presented. Where quantitative data is being presented, the number of studies that inform the outcome, the number of participants (from included studies) and the heterogeneity of the results of included reviews should also be reported (Smith et al, 2011). Where the results of qualitative systematic reviews are included in the Umbrella Review, the final or overall synthesized findings from included reviews should be presented, also in tabular format and with enough relevant contextual information alongside each synthesized finding to ensure each is interpretable to the reader of the Umbrella Review. Clear indication of any overlaps of original research studies in each of the included research syntheses must also be presented in the JBI Umbrella Review. For example, if one study is included in multiple syntheses this must be indicated.

The Principles from Grading of Recommendations Assessment, Development, and Evaluation (GRADE) should be used for an overall assessment of the quality of evidence for each intervention or phenomena of interest. The GRADE concept is based on an assessment of the following criteria: quality of primary studies, design of primary studies, consistency and directness (Guyat et al, 2008).