AMSTAR 2 is only partially applicable to systematic reviews of non-intervention studies: a meta-research study

A measurement tool to assess systematic reviews 2 (AMSTAR 2) was originally developed for systematic reviews (SRs) of health-care interventions. The aim of this study was to assess the applicability of AMSTAR 2 to SRs of non-intervention studies.This was a meta-research study. We used 20 SRs for each of the following four types of SRs: Diagnostic Test Accuracy reviews, Etiology and/or Risk reviews, Prevalence and/or Incidence reviews, and Prognostic reviews (80 in total). Three authors applied AMSTAR 2 independently to each included SRs. Then, the authors assessed the applicability of each item to that SR type and any SR type.Researchers unanimously indicated that 7 of 16 AMSTAR 2 items were applicable for all four specific SR types and any SR type (items 2, 5, 6, 7, 10, 14 and 16), but 8 of 16 items for any SR type. These items could cover generic SR methods that do not depend on a specific SR type.AMSTAR 2 is only partially applicable for non-intervention SRs. There is a need to adapt/extend AMSTAR 2 for SRs of non-intervention studies. Our study can help to further define generic methodological aspects shared across SR types and methodological expectations for non-intervention SRs.