Table 3 Design quality of included trials
Study | Region | Sequence generation | Allocation concealment | Blind | Outcome data | Selective outcome reporting | Other sources of bias | ITT | Risk of bias |
|---|---|---|---|---|---|---|---|---|---|
Guo Y 2004 [13] | Single center | Random number table (SPSS) | Unclear | Unclear | Yes | No | Unclear | Yes | Unclear risk of bias |
Lei H 2006 [14] | Single center | Random number table (SPSS) | Unclear | Unclear | Yes | No | Unclear | Yes | Unclear risk of bias |
Wang H 2007 [15] | Single center | Random number table (SPSS) | Clear | Unclear | Yes | No | Unclear | Yes | Unclear risk of bias |
Wu S 2009 [16] | Single center | Random number table (SPSS) | Unclear | Unclear | Yes | No | Unclear | Yes | Unclear risk of bias |
Fu X 2009 [17] | Single center | Random number table (SPSS) | Unclear | Unclear | Yes | No | Clear | Yes | Low risk of bias |
Chen Y 2011 [18] | Single center | Random number table (SPSS) | Unclear | Unclear | Yes | No | Unclear | Yes | Unclear risk of bias |
Jia L 2011 [19] | Single center | Random number table (SPSS) | Unclear | Unclear | Yes | No | Unclear | Yes | Unclear risk of bias |
Liu B 2012 [20] | Single center | Random number table (SPSS) | Unclear | Unclear | Yes | No | Clear | Yes | Low risk of bias |
Zhang J 2012 [21] | Single center | Random number table (SPSS) | Unclear | Unclear | Yes | No | Clear | Yes | Low risk of bias |
Zhang H 2013 [22] | Single center | Random number table (SPSS) | Unclear | Unclear | Yes | No | Clear | Yes | Low risk of bias |
Yang G 2014 [23] | Multiple center | Random number table (SPSS) | Unclear | Unclear | Yes | No | Clear | Yes | Low risk of bias |
Yang H 2014 [24] | Single center | Random number table (SPSS) | Unclear | Unclear | Yes | No | Clear | Yes | Low risk of bias |
Yue K 2016 [25] | Single center | Random number table (SPSS) | Unclear | Clear | Yes | No | Clear | Yes | Low risk of bias |
Wang C 2016 [26] | Single center | Random number table (SAS) | Unclear | Unclear | Yes | No | Clear | Yes | Low risk of bias |