Table 2.

Risk of bias assessment in each study according Cochrane Collaboration Tool.

Author (Year)	Selection Bias		Performance bias	Detection bias	Attrition bias	Reporting bias	Others
	Randomization	Allocation concealment	Blinding of participants and staff	Blinding of outcome assessors and results	Monitoring, exclusion and abandonment	Selective reporting of results	Other biases
Smolen et al. (2018)*	Low	Low	Low	Low	Low	Low	Low
Jorgensen et al. (2017)*	Low	Low	Low	Low	Low	Low	Low
Tanaka (2017)	High	High	High	High	Low	Low	Low
Yoo et al. (2017)	High	High	High	High	Low	Low	Low
Park et al. (2017)	High	High	High	High	Low	Low	Low

* These articles respond directly PICOs question.