TABLE 1.
Risk of bias of the included randomized controlled trials1
| Study ID | Random sequence generation | Allocation concealment | Blinding of participants and personnel | Blinding of outcome assessment | Incomplete outcome data | Selective reporting | Other bias |
|---|---|---|---|---|---|---|---|
| Boehm et al. (27) | Unclear | Unclear | Unclear | Unclear | Low | Low | Unclear |
| Cristofalo et al. (29) | Unclear | Unclear | Low | Low | Low | Low | High |
| Hagelberg et al. (26) | Unclear | Unclear | Unclear | Unclear | Low | Low | Unclear |
| O'Connor et al. (28) | Low | Low | Low | Low | Low | Low | Low |
| Polberger et al. (25) | Unclear | Low | High | High | Low | Low | Unclear |
| Sullivan et al. (24) | Low | Unclear | High | Low | Unclear | Low | High |
1
Low risk: clearly defined random sequence generation, allocation concealment, blinding of participants, and outcome assessment, no incomplete data, no selective reporting. Unclear risk: information about any of the risk assessors not defined. High risk: random sequence generation, allocation concealment, blinding, and data outcome not done, selective reporting possible.