Table 2.
Risk of bias for the 19 included studies using a modified approach to the Cochrane risk of bias tool.
| Risk of bias | Trial characteristics | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Source | Random sequence generation | Allocation concealment | Blinding of participants and personnel | Blinding of outcome assessors | Infrequent loss to follow-up | Free of selective outcome reporting | Free of other types of bias | Statistical analysis (per protocol, intention to treat, etc.) | How is loss to follow-up handled? | Adverse event |
| Wang (2018) [10] | Definitely yes | Definitely yes | Probably no | Probably no | Definitely no | Definitely no | Definitely no | Not mentioned | Ignored | Yes |
|
| ||||||||||
| Wang (2016) [11] | Probably yes | Probably yes | Probably no | Probably no | Definitely yes | Definitely yes | Probably yes | Not mentioned | Not mentioned | Yes |
|
| ||||||||||
| Zhong (2016) [12] | Definitely yes | Definitely yes | Probably no | Probably no | Definitely yes | Definitely no | Probably yes | Per protocol | Not mentioned | No |
|
| ||||||||||
| Mi (2010) [13] | Definitely yes | Definitely yes | Probably no | Probably no | Definitely yes | Definitely yes | Probably yes | Not mentioned | Not mentioned | Yes |
|
| ||||||||||
| Bai (2019) [14] | Definitely yes | Definitely yes | Probably no | Probably no | Definitely yes | Definitely yes | Probably yes | Not mentioned | Not mentioned | Yes |
|
| ||||||||||
| Liu (2018) [15] | Definitely yes | Definitely yes | Probably no | Probably no | Definitely no | Definitely yes | Probably yes | Not mentioned | Ignored | Yes |
|
| ||||||||||
| Liu (2011) [16] | Definitely yes | Definitely yes | Probably no | Probably no | Definitely yes | Definitely yes | Probably yes | Not mentioned | Not mentioned | Yes |
|
| ||||||||||
| Fu (2019) [17] | Definitely yes | Definitely yes | Probably no | Probably no | Definitely no | Definitely no | Definitely no | Per protocol | Ignored | Yes |
|
| ||||||||||
| Wu (2019) [18] | Definitely yes | Definitely yes | Probably no | Probably no | Definitely yes | Definitely no | Probably yes | Not mentioned | Not mentioned | Yes |
|
| ||||||||||
| Dong (2018) [19] | Probably yes | Probably yes | Probably no | Probably no | Definitely yes | Definitely yes | Probably yes | Not mentioned | Not mentioned | Yes |
|
| ||||||||||
| Sun (2016) [20] | Probably yes | Probably yes | Probably no | Probably no | Definitely yes | Definitely yes | Probably yes | Not mentioned | Not mentioned | Yes |
|
| ||||||||||
| Zhang (2014) [21] | Probably yes | Probably yes | Probably no | Probably no | Definitely yes | Definitely yes | Probably yes | Per protocol | Not mentioned | Yes |
|
| ||||||||||
| Hui (2019) [22] | Definitely yes | Definitely yes | Probably no | Probably no | Definitely yes | Definitely yes | Probably yes | Not mentioned | Not mentioned | Yes |
|
| ||||||||||
| Tan (2012) [23] | Probably yes | Probably yes | Probably no | Probably no | Definitely yes | Definitely no | Probably yes | Not mentioned | Not mentioned | Yes |
|
| ||||||||||
| Fan (2017) [24] | Definitely yes | Definitely yes | Probably no | Probably no | Definitely yes | Definitely yes | Probably yes | Per protocol | Not mentioned | No |
|
| ||||||||||
| Jiang (2016) [25] | Probably yes | Probably yes | Probably no | Probably no | Definitely yes | Definitely no | Probably yes | Per protocol | Not mentioned | No |
|
| ||||||||||
| Li (2017) [26] | Probably yes | Probably yes | Probably no | Probably no | Definitely yes | Definitely yes | Probably yes | Not mentioned | Not mentioned | Yes |
|
| ||||||||||
| Huang (2018) [27] | Probably yes | Probably yes | Probably no | Probably no | Definitely yes | Definitely yes | Probably yes | Not mentioned | Not mentioned | No |
|
| ||||||||||
| Peng (2012) [28] | Probably yes | Probably yes | Probably no | Probably no | Definitely yes | Definitely yes | Probably yes | Per protocol | Not mentioned | No |