Risk of bias assessment: randomised controlled trials (Cochrane Risk of Bias 2 Tool)
| Study | Sequence generation | Allocation concealment | Blinding of participants | Blinding of outcome assessors | Incomplete data | Selective outcome reporting | Other sources | Overall |
| Fleming et al 55 | High | Low | Low | Some concerns | Some concerns | Low | Low | High |
| Mohtadi et al 68 | Low | Low | Low | Low | Low | Low | Low | Low |