“…The second search, conducted on March 8–9, 2021, found an additional 574 records, and the third search, done on July 27, 2021, found an additional 1691 records, resulting in 3196 unique records overall, after deduplication. After title and abstract screening, 173 articles were retained for full-text review, of which 12 19 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 fulfilled our inclusion and exclusion criteria ( appendix p 7 ). All studies were observational, and seven were strictly retrospective; 19 , 30 , 31 , 32 , 35 , 38 , 40 although some researchers implemented control procedures, no RCTs were reported.…”