Study | Random sequence generation | Allocation concealment | Blinding of participants and personnel | Blinding of outcome | Incomplete outcome data | Selective reporting | Other biases | Overall risk of bias |
---|---|---|---|---|---|---|---|---|
Fang 2015 | low | low | low | unclear | low | low | low | moderate |
Wehmeyer 2014 | low | low | low | unclear | low | low | low | moderate |
Li 2019 | unclear | unclear | unclear | unclear | low | low | low | moderate |
Zhang 2017 | low | unclear | unclear | unclear | low | low | low | moderate |
Ma 2018 | unclear | unclear | unclear | unclear | low | low | low | moderate |