Table S1.
Quality assessment of included studies
| Study | Random sequence generation |
Allocation concealment |
Blinding | Incomplete outcome data addressed |
Free of selective reporting |
Other sources of bias |
Quantity | ||
|
| |||||||||
| Participants | Personnel | Outcome assessors | |||||||
| Szwejkowskiet al [22], 2013 |
Yes | Yes | Yes | Yes | Yes | Yes | Yes | Not reported | High |
| Perez-Pozo et al [23], 2010 |
Yes | Yes | Yes | No | Not reported | Yes | Yes | Not reported | Medium |
| Takir et al [24], 2014 | Unclear | Unclear | Unclear | Unclear | Not reported | Yes | Yes | Not reported | Low |
| Liu et al [25], 2015 | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Not reported | High |
| Ding et al [26], 2012 | Unclear | Unclear | Unclear | Unclear | Not reported | Unclear | Yes | Not reported | Low |
| Le et al [27], 2013 | Unclear | Unclear | Unclear | Unclear | Not reported | Yes | Yes | Not reported | Low |
| Ogino et al [28], 2016 | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Not reported | High |