Acupuncture for Erectile Dysfunction: A Systematic Review

Figure 2

Risk of bias assessment. The percentages of studies with “low risk of bias,” “high risk of bias,” or “unclear risk of bias” are illustrated for each item of Cochrane Collaboration’s tool. The assessment of risk of bias due to treatment group size: <50 participants per group indicated high risk of bias, 50–199 indicated unclear risk, and 200 or more indicated low risk.