“…In addition, a manual search yielded 687, 374, and 500 records from the WHO Global Research Database on COVID-19, LitCovid, and Google Scholar, respectively. We finally identified 40 studies, of which 25 were further included in the meta-analysis 9 , 10 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 and 15 were excluded owing to incomplete information or data. 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 The detailed search results are presented in the PRISMA flowchart in Fig.…”