Table 6.

Evaluation of the quality of randomized controlled trials.

Author (year)	Selection bias (randomization sequence generation)			Selection bias (allocation concealment)			Performance bias			Detection bias			Attrition bias			Reporting bias			Other biases
	High risk	Low risk	Unclear	High risk	Low risk	Unclear	High risk	Low risk	Unclear	High risk	Low risk	Unclear	High risk	Low risk	Unclear	High risk	Low risk	Unclear	High risk	Low risk	Unclear
Seto (2014) [12]		√			√		√			√				√			√			√
Kitagawa (2019) [19]		√			√				√			√		√			√			√
Stinchcombe (2019) [20]		√			√				√			√		√			√			√
Saito (2019) [13]		√			√		√			√				√			√			√
Nakagawa (2019) [15]		√			√			√			√			√			√			√
Zhou (2019) [14]		√			√				√			√		√			√			√