Table 2. Assessment of risk of bias in RCT.

Study	Selection bias			Performance bias		Detection bias		Attrition bias		Reporting bias	Other bias
	Random sequence generation	Allocation concealment		Blinding of participants and personnel		Blinding of outcome assessment		Incomplete outcome data		Selective reporting
Lee 2004 (48)	Unclear	Unclear		Low		Unclear		Low		Unclear	Unclear

RCT, randomized controlled trial.