Table 3.

Quality assessment of included randomized controlled trials.

Included trials	Random sequence generation	Allocation concealment	Blinding of participants and personnel	Blinding of outcome assessment	Incomplete outcome data	Selective reporting	Other sources of bias	Risk of bias
Zheng, 2011 [40]	Table of random number	Unclear	Unclear	Unclear	No	No	Unclear	Unclear
Xiong, 2010 [41]	Unclear	Unclear	Unclear	Unclear	Yes	No	Unclear	High
Chen et al., 2005 [42]	Unclear	Unclear	Unclear	Unclear	Yes	No	Unclear	High
Wang, 2001 [43]	Unclear	Unclear	Unclear	Unclear	Yes	No	Unclear	High
Che et al., 2011 [44]	Table of random number	Unclear	Unclear	Unclear	No	No	Unclear	Unclear
Jin, 2011 [45]	Unclear	Unclear	Unclear	Unclear	No	No	Unclear	High
Chen, 2007 [46]	Table of random number	Unclear	Unclear	Unclear	Yes	No	Unclear	Unclear
Guo, 2009 [47]	Unclear	Unclear	Unclear	Unclear	Yes	No	Unclear	High
Li, 2011 [48]	Drawing	Unclear	Unclear	Unclear	Yes	No	Unclear	Unclear
Guo et al., 2006 [49]	Unclear	Unclear	Unclear	Unclear	Yes	No	Unclear	High
Zhou, 2008 [50]	Unclear	Unclear	Unclear	Unclear	No	No	Unclear	High
Wu et al., 2007 [51]	Unclear	Unclear	Unclear	Unclear	Yes	No	Unclear	High
Lei and Lin, 2009 [52]	Unclear	Unclear	Unclear	Unclear	Yes	No	Unclear	High
Liu et al., 2007 [53]	Unclear	Unclear	Unclear	Unclear	Yes	No	Unclear	High
Zhang, 2002 [54]	Table of random number	Unclear	Unclear	Unclear	Yes	No	Unclear	High
Wang, 2005 [55]	Unclear	Unclear	Unclear	Unclear	Yes	No	Unclear	High