Table 1.

Risk of bias summary.

Trials	Random sequence generation	Allocation concealment	Blinding of participants and personnel	Blinding of outcome assessment	Incomplete outcome data	Selective reporting	Other bias
Gou et al. (25)	High	High	High	Unclear	Low	Low	Low
Han et al. (26)	Unclear	Unclear	Unclear	Unclear	Low	Low	Low
Hong et al. (27)	Unclear	Unclear	High	Unclear	Low	Low	Low
Li (28)	High	High	High	Unclear	Low	Low	Low
Liu et al. (29)	Low	Unclear	High	Unclear	Low	Low	Low
Ma et al. (30)	Low	Low	High	Low	High	Low	Low
Park et al. (31)	Low	Low	High	Low	Low	Low	Low
Shou et al. (32)	Unclear	Unclear	Unclear	Unclear	Low	Low	Low
Sun et al. (33)	Unclear	Low	Low	Low	Low	Low	Low
Xiao et al. (34)	Low	Unclear	High	Unclear	Low	Low	Low
Xu et al. (35)	Low	Unclear	Unclear	Unclear	Low	Low	Low
Zhang (36)	Low	Unclear	Unclear	Unclear	Low	Low	Low
Zheng et al. (37)	Unclear	Unclear	High	High	Low	Low	Low