Table 3: Risk of bias of included studies.

Study IDAdequate sequence generationRandom sequence generation
(selection bias)
Allocation concealment
(selection bias)
Blinding of participants and personnel
(performance bias)
Blinding of outcome assessment
(detection bias)
Incomplete outcome data
(attrition bias)
Selective reporting
(reporting bias)
Other bias

Fujimori et al., 2001 [26]NSUnclear riskUnclear riskUnclear riskUnclear riskLow riskLow riskHigh risk
Irifune et al., 2011 [27]NSUnclear riskUnclear riskHigh riskHigh riskLow riskUnclear riskUnclear risk
Qin, 2011 [28]NSUnclear riskUnclear riskUnclear riskUnclear riskLow riskUnclear riskUnclear risk
Wang, 2011 [29]NSUnclear riskUnclear riskHigh riskHigh riskUnclear riskUnclear riskUnclear risk
Song, 2012 [30]YesLow riskUnclear riskUnclear riskUnclear riskUnclear riskUnclear riskUnclear risk
Wu et al., 2011 [31]YesLow risk Unclear riskUnclear riskUnclear riskLow riskUnclear riskUnclear risk
Zhang et al., 2008 [32]YesLow riskLow riskLow riskUnclear riskUnclear riskLow riskLow risk
Wu, 2011 [33]YesLow riskLow riskLow riskLow riskLow riskLow riskLow risk
An, 2002 [34]NSUnclear riskUnclear riskHigh riskHigh riskUnclear riskUnclear riskUnclear risk
Jiang, 2013[35]YesLow riskLow riskLow riskLow riskLow riskLow riskLow risk
Min, 2011 [36]YesLow riskUnclear riskUnclear riskUnclear riskUnclear riskUnclear riskUnclear risk
Huang, 2009 [37]NoHigh riskHigh riskUnclear riskUnclear riskLow riskUnclear riskUnclear risk