Table 4 Risk of bias of the included studies
First author (publication year) | Bias due to confounding | Bias in selection of participants into the study | Bias in classification of interventions | Bias due to deviations from intended interventions | Bias due to missing data | Bias in measurement of outcomes | Bias in selection of the reported result | Overall risk of bias |
|---|---|---|---|---|---|---|---|---|
Özdoğan (2020) | Low | Low | Moderate | Low | No information | Low | Low | Moderate |
Inoue (2018) | Serious | Low | Low | Low | No information | Low | Low | Serious |
Endo (2017) | Moderate | Low | Low | Low | No information | Low | Low | Moderate |
Kan (2017) | Low | Low | Low | Low | No information | Low | Low | Low |
Notsumata (2017) | Serious | Low | Moderate | Low | No information | Low | Low | Serious |
Hashimoto (2016) | Low | Low | Low | Low | No information | Low | Low | Low |