“…Eighteen trials were conducted in upper middle-income countries [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 ], nine in lower middle-income countries [ 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ] and two in low-income countries [ 48 , 49 ]. The total sample size was 16,670, with individual study participants ranging from 41 [ 49 ] to 8120 [ 40 ], with 11 of the 30 studies included having a sample size greater than 200.…”