“…Most of the studies were rated to have a low risk of bias ( n = 35) 10 , 17–27 , 29 , 31 , 33–35 , 38 , 39 , 41–44 , 46 , 47 , 49–54 , 56 , 60–62 , and 12 studies had a moderate level of risk of bias 28 , 30 , 32 , 36 , 37 , 40 , 45 , 48 , 55 , 57–59 ( Supplementary Appendix 7 ). The risk of bias primarily arose from a lack of reporting on the sampling frame ( n = 28) 10 , 17 , 28–30 , 32–34 , 37 , 38 , 40 , 41 , 43–48 , 50 , 52–55 , 57–59 , 61 , 62 and the sampling method where convenience sampling or voluntary sample was used ( n = 20). 17 , 21 , 22 , 27 , 29–31 , 33 , 36 , 38 , 42–44 , 46 , 47 , 49 , 50 , 52 , 56 , 58 Hence, there was uncertainty on whether the true close representation of the target population was established.…”