Figure 2.

Risk of bias assessment for all comparisons with 20 or more participants per group (n = 128). Overall risk-of-bias was judged “High” if at least one domain had a rating of high risk-of-bias or if there were concerns in more than one domain. The overall rating of “Some concerns” was given if there were concerns in any one domain, and “Low” if all domains were rated as of low risk-of-bias, as per the Cochrane Risk of Bias tool 2 (RoB 2).⁷¹