Table 2.

Risk of Bias in Included Randomized Controlled Trials

Author, Year	Random sequence generation	Allocation concealment	Blinding of participants and personnel	Binding of outcome assessment	Incomplete outcome data	Selective reporting	Other bias
Xie et al., 2012	Unclear	Unclear	Unclear	Unclear	Low risk	Low risk	Unclear
Li et al., 2012	Low risk	Unclear	Unclear	Unclear	Low risk	Low risk	Low risk
Kang et al., 2011	Low risk	Low risk	Unclear	Unclear	Low risk	Low risk	Low risk
Sun et al., 2011	Unclear	Unclear	Unclear	Unclear	Low risk	Low risk	High risk
Jiang et al., 2011	Low risk	Low risk	Unclear	Unclear	Low risk	Low risk	Low risk
Jia et al., 2011	Unclear	Unclear	Unclear	Unclear	Low risk	Low risk	Low risk
Yang et al., 2011	Low risk	Low risk	Unclear	Unclear	Low risk	Low risk	Low risk
Rao et al., 2010	Unclear	Unclear	Unclear	High risk	Low risk	Low risk	Low risk
Wu et al., 2010	Unclear	Unclear	Unclear	Unclear	Low risk	Low risk	High risk
Lin et al., 2010	Unclear	Unclear	Unclear	Unclear	Low risk	Low risk	Low risk
Zhu et al., 2010	Unclear	Unclear	Unclear	Unclear	Low risk	Low risk	Unclear
Wang et al., 2009	High risk	Unclear	Unclear	Unclear	Low risk	Low risk	Low risk
Guo et al., 2009	Low risk	Unclear	Unclear	Low risk	Low risk	Low risk	Low risk
Chou et al., 2009	Unclear	Unclear	Unclear	Low risk	Low risk	Low risk	Low risk
Wang et al., 2008	Unclear	Unclear	Unclear	Unclear	Low risk	Low risk	Low risk
Huang et al., 2008	Low risk	Unclear	Unclear	Unclear	Low risk	Low risk	Unclear
Li et al., 2008	Unclear	Unclear	Unclear	Unclear	Low risk	Low risk	Low risk
Yu et al., 2007	High risk	Unclear	Unclear	Unclear	Low risk	Low risk	Unclear
Guo et al., 2007	Low risk	Unclear	Unclear	Low risk	Low risk	Low risk	High risk
Liu et al., 2006	Low risk	Unclear	Unclear	Low risk	Low risk	Low risk	Low risk
Yang et al., 2006	Low risk	Low risk	Unclear	High risk	Low risk	Low risk	Low risk

Based on Cochrane Handbook for Systematic Reviews of Interventions, Part 2: 8.5.