Table 1 Definition of “overview of reviews” [18]

1. Contains a clearly formulated objective designed to answer a specific research question, typically about a healthcare intervention.

2. Intends to search for and include only systematic reviews (with or without meta-analyses).

3. Uses explicit and reproducible methods to identify multiple systematic reviews that meet the overview of reviews’ inclusion criteria and assess the quality/risk of bias of these systematic reviews.

4. Intends to collect, analyze, and present the following data from included systematic reviews: descriptive characteristics of the systematic reviews and their included primary studies; risk of bias of primary studies; quantitative outcome data; and certainty of evidence for pre-defined, clinical important outcomes.

5. Discusses findings as they relate to the purpose, objective(s), and specific research question(s) of the overview of reviews, including: a summary of main results, overall completeness and applicability of evidence, quality of evidence, potential biases in the overview process, and agreements and/or disagreements with other studies and/or reviews.