Table 2:
Risk-of-bias review of included studies
| Study | Random sequence generation (selection bias) | Allocation concealment (selection bias) | Blinding (performance bias and detection bias) | Incomplete outcome data (attrition bias) | Selective reporting (reporting bias) | Other bias |
|---|---|---|---|---|---|---|
| Al-Nakib et al.26 | Unclear | Unclear | Low | Low | High | High |
| Douglas et al.27 | Unclear | Unclear | Low | High | Unclear | High |
| Eby et al.28 | Unclear | Unclear | Low | High | Low | High |
| Farr et al. (A)29 | Low | Unclear | Low | Unclear | High | Unclear |
| Farr et al. (B)29 | Low | Unclear | Low | Unclear | Unclear | Unclear |
| Godfrey et al.30 | Low | Low | Low | High | Unclear | Unclear |
| Kurugöl et al.31 | Low | Unclear | Low | Low | Low | Low |
| Kurugöl et al.32 | Low | Low | Low | Low | Low | Low |
| Macknin et al.33 | Low | Low | Low | Low | Low | Low |
| Mossad et al.34 | Low | Low | Low | Low | Low | Unclear |
| Petrus et al.34 | Unclear | Unclear | Low | Low | Unclear | Unclear |
| Prasad et al.36 | Low | Low | Low | Low | Low | Low |
| Prasad et al.37 | Low | Low | Low | Low | Low | Low |
| Smith et al.38 | Unclear | Unclear | Low | High | High | Unclear |
| Turner et al. (A)24 | Unclear | Unclear | Low | High | Low | Unclear |
| Turner et al. (B)24 | Unclear | Unclear | Low | High | Low | Unclear |
| Weismann et al.39 | Unclear | Unclear | Low | High | High | Unclear |