Table 2.

The risk-of-bias table in this meta-analysis

	Chen CM [25]	Feng Y [26]	Guo ZP [27]	Li J [28]	Ren HL [29]	Wang W [30]	Xiao L [31]	Yuan WQ [32]	Zhai HL [33]	Zhang L [34]	Zhang LG [35]	Zhang X [36]	Zhao XQ [37]	Zhou R [38]
Random sequence generation	Low	Low	Low	Low	Low	Low	Low	Low	Low	Low	Low	Low	Low	Low
Allocation concealment	Not	Not	Not	Not	Not	Not	Not	Not	Not	Not	Not	Not	Not	Not
Blinding of participants and personnel	High	High	High	High	High	High	High	High	High	High	High	High	High	High
Blinding of outcome assessment	Low	Low	Low	Not	Low	High	Low	High	Low	Low	Low	Low	High	High
Incomplete outcome data	Low	Low	Low	Low	Low	Low	Low	Low	Low	Low	Low	Low	Low	Low
Selective reporting	Not	Low	Not	High	Not	High	Low	Low	Low	Low	Low	High	Low	Low
Other biases	Low	Low	Low	Not	Not	Low	Not	Not	Not	Low	Low	High	Not	Low

Note: In this table, “Low” stands for low risk, “High” stands for high risk, and “Not” stands for not clear