Table 2.
Risk of bias in included studies
| Author/year | Randomization | Allocation concealment | Blinding of participants | Blinding of outcome assessment | Incomplete outcome data | Selective outcome reporting | Other bias |
|---|---|---|---|---|---|---|---|
| Fan 2014 | Low | Unclear | Low | Low | Low | Low | Unclear |
| Hakkalamani 2015 | Low | Low | Low | Low | Low | Low | Unclear |
| Harvey 1997 | Unclear | Unclear | Low | Low | Low | Low | Unclear |
| Kvederas 2013 | Low | Low | Low | Low | Low | Low | Unclear |
| Mittal 2012 | Low | Low | Low | Low | Low | Low | Unclear |
| Tarwala 2014 | Low | Unclear | Low | Low | Low | Low | Unclear |
| Wang 2016 | Low | Low | Low | Low | Low | Low | Unclear |