Background and Objectives
As the quantity of published systematic reviews has increased substantially over the years, concerns about the methodological quality of this growing body of literature have been validly raised. AMSTAR 2, the updated version of AMSTAR, is an endorsed appraisal instrument aiming to critically assess the methodological aspects of a systematic review from conception to conduct and interpretation of the findings. However, since the publication of AMSTAR 2, several critiques have been expressed targeting various aspects of the instrument. The present commentary focuses on the AMSTAR 2 items that involve the appropriateness of statistical methods (item 11) and publication bias (item 15).
Methods
The refinements are based on the methodological advances in meta-analysis as summarized in the Cochrane Handbook and delineated in review methodological studies.
Results
Initially, the commentary outlines further issues and challenges with the formulation and implementation of AMSTAR 2 items 11 and 15, beyond those already raised by other authors. Then, refinements to the corresponding decision points of items 11 and 15 are suggested, with explanations for their importance in facilitating an evidence-based, transparent, and consistent evaluation among the involved appraisers.
Conclusion
The commentary strongly recommends that appraisers consult with meta-analysts when assessing the statistical methods of a systematic review and refer to the Cochrane Handbook, as it is regularly updated with recent methodological advances in meta-analysis. The appraisal teams could use the suggested refinements as a basis to predetermine the decision points for items 11 and 15 that align with the statistical expectations of the assessed systematic review, thereby preventing any ambiguity during the rating process.
