Table 2.
Risk of bias in the assessment of the studies.
| Study | Random sequence generation | Allocation concealment | Blinding of participants and personnel | Blinding of outcome assessment | Incomplete outcome data | Selective outcome reporting | Other sources of bias |
|---|---|---|---|---|---|---|---|
| Vigorito | L | L | — | L | L | U | L |
| Giallauria | U | U | — | L | L | L | L |
| Stener-victorin | L | L | — | L | H | L | L |
| Almenning | L | L | — | L | H | L | L |
| Vizza | L | L | — | U | H | L | L |
| Orio | L | L | — | L | L | U | L |
| Costa | L | L | — | U | L | L | L |
| Faryadian | H | H | — | U | L | L | U |
| Nybacka | L | L | — | U | H | L | U |
U: unclear risk of bias; L: low risk of bias; H: high risk of bias.