Table 4.

Assessment of study quality of randomised controlled trials

Study	Criteria	Risk of bias	Study quality
Kuchay et al[11]	Random sequence generation	Low risk	Good quality
	Allocation concealment	Low risk
	Selective reporting	Low risk
	Other bias	Low risk
	Blinding of participants and personnel	Low risk
	Blinding of outcome assessment	Low risk
	Incomplete outcome data	Low risk
Ito et al[12]	Random sequence generation	Low risk	Fair quality
	Allocation concealment	Unclear risk
	Selective reporting	Low risk
	Other bias	Low risk
	Blinding of participants and personnel	Low risk
	Blinding of outcome assessment	Low risk
	Incomplete outcome data	Low risk
Shibuya et al[13]	Random sequence generation	Unclear risk	Fair quality
	Allocation concealment	Unclear risk
	Selective reporting	Low risk
	Other bias	Low risk
	Blinding of participants and personnel	Low risk
	Blinding of outcome assessment	Low risk
	Incomplete outcome data	Low risk
Eriksson et al[14]	Random sequence generation	Low risk	Good quality
	Allocation concealment	Low risk
	Selective reporting	Low risk
	Other bias	Low risk
	Blinding of participants and personnel	Low risk
	Blinding of outcome assessment	Low risk
	Incomplete outcome data	Low risk