Table 2.
Risk of bias summary among RCTs (following the recommendations of Higgins & Green 2011)
| Random sequence generation (selection bias) | Allocation concealment (selection bias) | Blinding of participants and personnel (performance bias) | Blinding of outcome assessment (detection bias) | Incomplete outcome data (attrition bias) | Selective reporting (reporting bias) | Other bias | Within-study risk of bias tendency | |
|---|---|---|---|---|---|---|---|---|
| Canullo et al. (2012) | Low | Low | Low | Low | Low | Low | Low | Low risk of bias for all key domains |
| Canullo et al. (2010) | Low | Low | Low | High | High | Low | Low | High risk of bias in two key domains |
| Canullo et al. (2009) | Low | Low | Low | Low | Low | Low | Low | Low risk of bias for all key domains |
| Crespi et al. (2009) | High | High | High | High | Low | Low | Low | High risk of bias in four key domains |
| Enkling et al. (2011) | Low | High | Low | Low | Low | Low | Low | High risk of bias in one key domain |
| Fernández-Formoso et al. (2012) | Low | Low | High | Unclear | Low | Unclear | Unclear | High risk of bias in one key domain and unclear risk of bias in three key domains |
| Gultekin et al. (2013) | Low | Low | Low | High | High | Low | Low | High risk of bias in two key domains |
| Hürzeler et al. (2007) | High | High | Low | High | Low | Low | Unclear | High risk of bias in three key domains and unclear risk of bias in one key domain |
| Kielbassa et al. (2009) | Low | Low | Low | High | High | Low | Unclear | High risk of bias in two key domains and unclear risk of bias in one key domain |
| Peñarrocha-Diago et al. (2012) | Unclear | Unclear | Low | Low | High | Low | Unclear | High risk of bias in one key domain and unclear risk of bias in three key domains |
| Pieri et al. (2011) | Low | Low | Low | High | Low | Low | Low | High risk of bias in one key domain |
| Prosper et al. (2009) | Low | Low | Low | Low | High | High | Unclear | High risk of bias in two key domains and unclear risk of bias in one key domain |
| Telleman et al. (2012a) | Low | Low | Low | Unclear | High | Low | Low | High risk of bias in one key domain and unclear risk of bias in one key domain |
| Telleman et al. (2012b) | Low | Low | Low | Low | High | Low | Low | High risk of bias in one key domain |
| Trammell et al. (2009) | Low | High | Low | High | Low | Low | Unclear | High risk of bias in two key domains and unclear risk of bias in one key domain |