“…The studies showed an average risk of bias percentage of 43.7% (standard deviation (SD) 15.3%), indicating that on average the studies had a moderate risk of bias. Seven studies had a low risk of bias (<33.3%), 21 , 22 , 25 , 27 , 31 , 38 , 39 but three of them did not describe all the bias criteria 31 , 38 , 39 ( Table 3 ); 14 studies had a moderate risk of bias (between 33.3% and 66.7%), 18 , 20 , 23 , 24 , 26 , 28 – 30 , 33 – 37 , 40 11 of which 18 , 20 , 23 , 24 , 28 , 30 , 34 – 37 , 40 did not describe all bias criteria (see Appendix 1 for criteria). One study had a high risk of bias (≥66.7%).…”