Ten studies (52.6%) had an unclear risk of bias for random sequence generation, and three studies (15.8%) had a high risk of bias for random sequence generation. Fourteen studies (73.7%) had an unclear risk of bias for allocation concealment. Fourteen studies (73.7%) had a high risk of bias related to sample size and only one study met our criteria of low risk of bias for size. However, 15 studies (78.9%) had a low risk of bias for blinding of outcome assessment. Two studies (10.55) had a high risk of bias related to incomplete outcome data, and nine studies (47.4%) had an unclear risk of bias related to selective reporting. We evaluated overall quality of the evidence using GRADE (see: summary of findings Table for the main comparison; summary of findings Table 2). Domains of the quality of evidence assessment included study design limitations, inconsistency, indirectness, imprecision, and publication bias. We downgraded the GRADE quality of the evidence for all outcomes to very low because of observed imprecision, indirectness, imbalance between groups in many studies, and limitations of study design.