Table 4.
Risk of bias assessment of the included studies
| Study |
Random sequence generation |
Allocation concealment |
Blinding of participants and personnel |
Blinding of outcome assessment |
Incomplete outcome data |
Selective reporting |
Other bias |
|---|---|---|---|---|---|---|---|
| Arisan et al. [20] | + | - | - | ? | + | + | ? |
| Bassetti et al. [21] | + | - | - | + | + | + | ? |
| Esposito et al. [22] | + | - | - | + | + | + | + |
| Hallström et al. [23] | + | + | - | - | + | + | + |
| John et al. [24] | + | - | - | + | + | - | ? |
| Machtei et al. [25] | + | + | + | + | + | + | ? |
| Persson et al. [26] | + | - | - | ? | + | + | ? |
| Riben-Grundstrom et al. [27] | + | + | - | + | + | - | ? |
| Swierkot et al. [28] | + | - | - | + | + | + | + |
+ = low risk; ? = unclear risk; - = high risk.