Table 2.
Quality scores of the included randomized clinical trials.
| Author | Year of publication | Randomized | Randomization hide | Blinding | Withdrawal and exit | Jadad scores |
| Xiao-Xia Cheng[17] | 2001 | 1 | 1 | 1 | 0 | 3 |
| Xing-Cai He[18] | 2007 | 2 | 1 | 1 | 0 | 4 |
| Cai-Feng Zhu[19] | 2007 | 1 | 1 | 1 | 0 | 3 |
| Wen-Gang Guo[20] | 2014 | 2 | 1 | 1 | 0 | 4 |
| Hai-Yan Lv[21] | 2016 | 1 | 1 | 2 | 0 | 4 |
| Zhi-Jie Dang[22] | 2017 | 1 | 1 | 1 | 0 | 3 |
| Xu-dan Heng[23] | 2017 | 2 | 1 | 1 | 0 | 4 |
| Hui Feng[24] | 2014 | 1 | 1 | 1 | 0 | 3 |
| Xin-wei Wang[25] | 2010 | 2 | 1 | 1 | 0 | 4 |
| Xiao-hua Yan[26] | 2013 | 2 | 1 | 1 | 0 | 4 |
| Jiang Hai[27] | 2015 | 2 | 1 | 1 | 0 | 4 |
| Yan Liu[28] | 2012 | 2 | 1 | 1 | 0 | 4 |
| Qing-zhen Liu[29] | 2016 | 1 | 1 | 1 | 0 | 3 |
| Qiong-li Yin[30] | 2017 | 1 | 1 | 1 | 0 | 3 |
| Qiu-xia Wu[31] | 2009 | 1 | 1 | 1 | 0 | 3 |
| Jia-liang Guan[32] | 2009 | 2 | 1 | 1 | 1 | 5 |