Table 2.
Risk of bias summary.
| Trials | 1. Randomization process | 2. Deviations from intended interventions | 3. Missing outcome data | 4. Measurement of outcome data | 5. Selection of the reported results | Overall |
|---|---|---|---|---|---|---|
| Kirkman 2019, USA | Low risk | Some concerns | High risk | Low risk | High risk | High risk |
| Aoike 2018, Brazil | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk |
| Barcellos 2018,Brazil | Low risk | Low risk | Some concerns | Low risk | High risk | High risk |
| Beetham 2018, Australia | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk |
| Ikizler 2018, USA | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk |
| Hiraki 2017, Japan | Low risk | Low risk | Low risk | Low risk | High risk | High risk |
| Leehey 2016, USA | Low risk | Low risk | Some concerns | Low risk | Low risk | Some concerns |
| Tang 2016, China | Low risk | Low risk | Low risk | Low risk | Some concerns | Some concerns |
| Greenwood 2015, UK | Some concerns | Low risk | Low risk | Low risk | High risk | High risk |
| Van Craenenbroeck 2015, Belgium | Low risk | Low risk | Some concerns | Low risk | Low risk | Some concerns |
| Watson 2015, UK | Low risk | Low risk | Low risk | Low risk | Some concerns | Some concerns |
| Headley 2014, USA | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk |
| Rossi 2014, USA | Some concerns | Low risk | High risk | Low risk | Low risk | High risk |
| Headley 2012, USA | Some concerns | Low risk | High risk | Low risk | Some concerns | High risk |
| Mustata 2011, Canada | Low risk | Low risk | Low risk | Low risk | Some concerns | Some concerns |
| Leehey 2009, USA | Low risk | Low risk | Some concerns | Low risk | Some concerns | Some concerns |
| Castaneda 2001, USA | Some concerns | Low risk | Low risk | Low risk | High risk | High risk |
| Eidemak 1997, Denmark | Some concerns | Low risk | Low risk | High risk | Some concerns | High risk |