Study, year (reference) | Random sequence generation | Allocation concealment | Blinding of participants and personnel | Blinding of outcome assessment | Incomplete outcome data | Selective reporting |
---|---|---|---|---|---|---|
Anderson et al, 198735 | ? | ? | + | + | ? | ? |
Chan et al, 200739 | + | + | + | + | ? | ? |
Farci et al, 200443 | + | + | + | + | ? | ? |
Krogsgaard, 199828 | ? | ? | + | + | − | ? |
Liaw et al, 200427 | + | + | + | + | + | + |
Mazzella et al, 199953 | ? | ? | + | + | + | ? |
Robson et al, 199256 | ? | ? | + | + | ? | ? |
Waked et al, 199062 | ? | ? | + | + | ? | ? |
+, Low risk of bias; −high risk of bias; ?, unknown risk of bias.