Table 2.
Quality assessment of all the studies.
| Studies | Characteristics of studies | ||||||
|---|---|---|---|---|---|---|---|
| Random sequence generation (selection bias) | Allocation concealment (selection bias) | Blinding of participants and personnel (performance bias) | Blinding of outcome assessment (detection bias) | Incomplete outcome data (attrition bias) | Selective reporting (reporting bias) | Other bias | |
| Ban Niya·Baheti (22) | Low | Unclear | High | Unclear | Low | Low | Unclear |
| Cao and Chen (23) | Unclear | Unclear | High | Unclear | Low | Low | Unclear |
| Gao (24) | Low | Unclear | High | Unclear | Low | Low | Unclear |
| Li et al. (25) | High | Unclear | High | Unclear | Low | Low | Unclear |
| Mi et al. (26) | Unclear | Unclear | High | Unclear | Low | Low | Unclear |
| Dou et al. (27) | Unclear | Unclear | High | Unclear | Low | High | Unclear |
| Xia (28) | Low | Unclear | High | Unclear | Low | Low | Unclear |
| Zhan and Wan (29) | Unclear | Low | High | Unclear | Low | High | Unclear |
| Zhang and Liu (30) | High | Unclear | High | Unclear | Low | Low | Unclear |
| Zou (31) | Low | Unclear | High | Unclear | Low | Low | Unclear |
| Jiang et al. (32) | Unclear | Unclear | High | Unclear | Low | Low | Unclear |