Table 3.
Quality assessment of all included studies based on the risk of bias.
| Clinical trial | Random sequence generation |
Allocation concealment | Blinding for participants and personnel |
Blinding of outcome assessment |
Incomplete outcome data | Selective reporting | Other sources of bias |
|---|---|---|---|---|---|---|---|
| Smart et al. (68) | Low | Low | Unclear | Low | Low | Low | Low |
| Hollister et al. (69) | Low | Unclear | Low | Low | Low | High | Low |
| Ludwig et al. (70) | Low | Unclear | High | Low | Low | High | Low |
| Hollister et al. (69) | Low | Unclear | High | Low | Unclear | Unclear | High |
| Bowen et al. (72) | Low | Low | Low | Unclear | High | Low | Low |
| Johnson (71) | Low | Unclear | High | Unclear | Unclear | High | Unclear |
| Pahnke et al. (62) | Low | Unclear | Low | Low | High | Low | High |
| Tomsovic and Edwards (59) | Low | Low | High | Unclear | Low | Low | Low |
| Savage and McCabe (74) | Low | Low | High | Low | Low | Low | High |
| Savage et al. (70) | Low | Unclear | Low | Low | Low | Low | High |
| Gasser et al. (75) | Low | Low | Low | Low | Low | Low | Unclear |