Table 2.
Quality assessment of included studies.
| Author | Year | Random | Randomization concealment | Blind | Withdrawal/loss to follow up | Total score |
|---|---|---|---|---|---|---|
| Xiao Huizhong | 1990 | 0 | 0 | 0 | 1 | 1 |
| Che Juan | 1993 | 1 | 0 | 0 | 1 | 2 |
| Zhu Qiufen | 1994 | 1 | 0 | 0 | 1 | 2 |
| Wu Hongbo | 1998 | 1 | 0 | 0 | 1 | 2 |
| Qiu Xiaolong | 2006 | 1 | 0 | 0 | 1 | 2 |
| Zhang Guangli | 2008 | 1 | 0 | 0 | 1 | 2 |
| Tian Qiang | 2009 | 2 | 1 | 0 | 1 | 4 |
| Xin Yuwen | 2010 | 1 | 0 | 0 | 1 | 3 |
| Chang Xueli | 2011 | 0 | 0 | 0 | 1 | 1 |
| Cao Fadong | 2012 | 2 | 0 | 0 | 1 | 3 |
| Hu Jiaqian | 2013 | 0 | 0 | 0 | 1 | 1 |
| Wu Lei | 2013 | 2 | 0 | 0 | 1 | 3 |
| Zou Yan | 2014 | 1 | 0 | 0 | 1 | 2 |
| Li Shujuan | 2015 | 1 | 0 | 0 | 1 | 2 |
| Ge Xiaohang | 2016 | 2 | 1 | 0 | 1 | 4 |