Table 1. Search strategy of PubMed database.

#1 meta-analysis [Title/Abstract] OR meta-analyses [Title/Abstract] OR “systematic review” [Title/Abstract] OR “systematic reviews” [Title/Abstract] OR overview* [Title/Abstract] OR review* [Title/Abstract]

#2 “AMSTAR 2” [All Fields] OR “AMSTAR2” [All Fields] OR AMSTAR-2 [All Fields]

#3 #1 AND #2