“…All studies were systematic reviews, and 15 provided meta-analyses [ 23 , 24 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 ]. The study design of the original reviews included only randomised controlled trials (RCT) or cluster RCT [ 29 , 35 , 40 , 41 ], and mixed designs (RCT, cluster RCT, cross-over designs, quasi-experimental studies, cross-sectional, and cohort studies) [ 9 , 17 , 23 , 24 , 26 , 27 , 28 , 30 , 31 , 32 , 33 , 34 , 36 , 37 , 38 , 39 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , …”