Table 2 Risk of bias
Salek et al.[27] | Kabbabe et al.[28] | Xu et al.[29] | Kim et al.[30] | Lubis et al.[31] | Lho et al.[32] | Sung et al.[33] | Schiefer et al.[34] | Safran et al.[35] | .Chan et al.[36] | Chen A et al.[37] | Yano et al.[38] | Park et al.[39] | Mertens et al.[40] | Chen B et al.[41] | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Proper sequence generation (selection risk) | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? |
Selection hiding (selection bias) | + | ? | + | + | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? |
Blinding of participants and staff (implementation bias) | - | - | - | - | ? | - | - | - | - | - | - | - | - | - | - |
Blinding of outcome evaluators (detection bias) | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? |
Incomplete results data (wear bias) | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? |
Selective reporting of results (notification bias) | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? | ? |
Other sources of bias | + | + | + | + | + | + | + | + | + | + | + | + | + | + | + |