Table 2 Risk of bias summary
Study | Allocation (selection bias) | Allocation sequence concealment | Blinding of participants and staff (performance bias) | Blinding of outcome assessment (detection bias) | Incomplete outcome data addressed | Free of selective reporting | Free of other bias |
|---|---|---|---|---|---|---|---|
Bhardwaja et al. 2010 [33] | Low | Unclear | Low | Low | Low | Low | Unclear |
Raebel et al. 2007 [34] | Low | Unclear | Low | Unclear | Low | Low | Unclear |
Raebel et al. 2007 [20] | Low | Unclear | Low | Unclear | Low | Low | Unclear |
Humphries et al. 2007 [21] | High | High | High | Unclear | Low | Low | Unclear |
Mansour et al. 2010 [14] | High | High | High | Unclear | Low | Low | Unclear |