Risk of bias among included studies
| Cochrane Items | ||||||||
|---|---|---|---|---|---|---|---|---|
| Selection bias | Performance bias | Detection bias | Attrition bias | Reporting bias | ||||
| Study | Random sequence generation | Allocation concealment | Blinding of participants and personnel | Blinding of outcome assessment | Incomplete outcome data | Selective reporting | Other | No. of high, %* |
| De Lima et al.86 (2019) | Low | Low | Low | Low | Low | Low | Low | 0 |
| Deppermann et al.115 (2014) | High | Low | Low | Low | Unsure | Low | Low | 14.29 |
| Diefenbach et al.116 (2016) | High | Low | Low | Low | Low | Low | Low | 14.29 |
| Dilkov et al.87 (2017) | Low | Low | Low | Low | High | Low | Low | 14.29 |
| Herrmann et al.117 (2017) | High | Low | Low | Low | Low | Low | Low | 14.29 |
| Huang et al.118 (2018) | High | Low | Low | Low | Low | Low | Low | 14.29 |
| Mantovani et al.119 (2013) | High | Low | Low | Low | Low | Low | Low | 14.29 |
| Movahed et al.120 (2018) | High | Low | High | High | Low | Low | Low | 42.86 |
| Nasiri et al.121 (2020) | High | High | Low | Low | Low | High | Low | 42.86 |
| Notzon et al.88 (2015) | High | Low | High | High | Unsure | Low | Low | 42.86 |
| Prasko et al.122 (2007) | High | Low | Low | Low | Low | Low | Low | 14.29 |
↵* We calculated a percentage for each study, as the quotient of the number of “High” ratings and the total number of relevant items. The lower the percentage, the lower the overall risk of bias.