AMSTAR 2 is a common instrument to evaluate the methodology of SRs.
18 Two researchers (LPY/DLZ) independently assessed the methodology of SRs using AMSTAR2. AMSTAR2 has 16 items, including seven critical items (item 2/4/7/9/11/13/15) which can critically affect the validity of a SR and its conclusion. Each item was evaluated as “yes,” “partial yes,” and “no” according to the standard of AMSTAR 2 guideline.
18 The details of AMSTAR 2 items and the general rules for results of a SR are seen in
Appendix B. Discrepancies were solved by team discussion.
Assessment of Risk of Bias
ROBIS is a tool designed specifically to assess the risk of bias in SRs,