| Study | Random sequence generation | Allocation concealment | Blinding of participants and personnel | Blinding of outcome assessment | Incomplete outcome data | Selective reporting | Other bias |
|---|---|---|---|---|---|---|---|
| Siu 2006 | Low | Unclear | High | Unclear | Low | Unclear | Low |
| Goicoechea 2010 | Low | Unclear | High | Low | Low | Unclear | Low |
| Sircar 2015 | Low | Low | Low | Unclear | High | Low | Low |
| Saag 2016 | Unclear | Unclear | Low | Unclear | High | Unclear | Low |
| Schumacher 2008 | Unclear | Unclear | Unclear | Unclear | High | Unclear | Low |
| Hosoya 2014 | Low | Unclear | Unclear | Unclear | Low | Low | Low |
| Golmohammadi 2017 | Unclear | Unclear | Unclear | Unclear | Unclear | Unclear | Low |
| Gunawardhana 2018 | Low | Unclear | Low | Unclear | High | Unclear | Low |
| Saag 2019 | Low | Unclear | Low | Unclear | High | Low | Low |
| Mukri 2018 | Low | Unclear | High | Unclear | Low | Unclear | Low |
| Kimura 2018 | Low | Unclear | Unclear | Unclear | Low | Low | Low |