Table 6 Study quality: review authors’ judgments about each risk of bias item for each included study
Author | Year | Random sequence generation | Allocation concealment | Blinding of participants and personnel | Blinding of outcome assessment | Incomplete outcome data | Selective reporting | Other sources of bias |
|---|---|---|---|---|---|---|---|---|
Yu et al. | 2012 | Unclear risk | Unclear risk | Unclear risk | Unclear risk | Low risk | Unclear risk | Unclear risk |
Tang et al. | 2014 | Unclear risk | Unclear risk | Unclear risk | Unclear risk | Low risk | Unclear risk | Unclear risk |
Sun et al. | 2014 | Unclear risk | Unclear risk | Unclear risk | Unclear risk | Low risk | Unclear risk | Unclear risk |
Cui et al. | 2015 | Unclear risk | Unclear risk | Unclear risk | Unclear risk | Low risk | Unclear risk | Unclear risk |
Zhang et al. | 2016 | Unclear risk | Unclear risk | Unclear risk | Unclear risk | Low risk | Unclear risk | Unclear risk |
Wang H et al. | 2015 | Unclear risk | Unclear risk | Unclear risk | Unclear risk | Low risk | Unclear risk | Unclear risk |
Wang F et al. | 2017 | Random number table | Unclear risk | Unclear risk | Unclear risk | Low risk | Unclear risk | Unclear risk |
Zhao et al. | 2014 | Unclear risk | Unclear risk | Unclear risk | Unclear risk | Low risk | Unclear risk | Unclear risk |
Chen et al. | 2015 | Unclear risk | Unclear risk | Unclear risk | Unclear risk | Low risk | Low risk | Unclear risk |
Huang et al. | 2015 | Random number table | Unclear risk | Unclear risk | Unclear risk | Low risk | Unclear risk | Unclear risk |
Lin et al. | 2017 | Unclear risk | Unclear risk | Unclear risk | Unclear risk | Low risk | Unclear risk | Unclear risk |
Zhang et al. | 2017 | Unclear risk | Unclear risk | Unclear risk | Unclear risk | Low risk | Unclear risk | Unclear risk |
Yang et al. | 2017 | Low risk | Unclear risk | Unclear risk | Unclear risk | Low risk | Low risk | Unclear risk |
Tian et al. | 2017 | Low risk | Unclear risk | Unclear risk | Unclear risk | Low risk | Low risk | Unclear risk |