Table 2.
Assessment of risk of bias using Cochrane risk of bias assessment tool (low risk versus high risk versus unclear), max. score 8 (higher score meaning a lower risk of bias).
| Study | Score (out of 8) | Random sequence generation | Allocation concealment | Blinding of participants | Blinding of study personnel | Assessor blinding | Incomplete outcome data | Selective reporting | Other bias |
|---|---|---|---|---|---|---|---|---|---|
| Al-Amran et al.44 | 3 | High | High | High | High | High | Low | Low | Low |
| Arnavaz et al.37 | 8 | Low | Low | Low | Low | Low | Low | Low | Low |
| Chan et al.46 | 2 | High | High | High | High | High | Low | Low | High |
| Dhar et al.51 | 2 | High | High | High | High | High | Low | Low | High |
| Diomedi et al.38 | 8 | Low | Low | Low | Low | Low | Low | Low | Low |
| Jahshan et al.52 | 3 | High | High | High | High | High | Low | Low | Low |
| Kruuse et al.39 | 8 | Low | Low | Low | Low | Low | Low | Low | Low |
| Kruuse et al.40 | 8 | Low | Low | Low | Low | Low | Low | Low | Low |
| Kruuse et al.47 | 3 | High | High | High | High | High | Low | Low | Low |
| Lindberg et al.42 | 8 | Low | Low | Low | Low | Low | Low | Low | Low |
| Lorberboym et al.48 | 1 | High | High | High | High | High | Unclear | High | Low |
| Lorberboym et al.43 | 3 | Unclear | High | High | High | High | Low | Low | Low |
| Mukherjee et al.49 | 2 | High | High | High | High | High | Low | Unclear | Low |
| Rosengarten et al.45 | 2 | High | High | High | High | High | Low | Low | High |
| Van Osta et al.41 | 8 | Low | Low | Low | Low | Low | Low | Low | Low |
| Washington et al.50 | 2 | High | High | high | High | Unclear | Low | Low | High |