Table 3.

Cochrane summary assessment of risk of bias for included RCTs

Study	Sequence generation	Allocation concealment	Blinding	Incomplete outcome data	Selective outcome reporting	Other sources of bias	Risk of biasa
Biffi, 2009	yes	yes	yes	yes	yes	no	low
Ribeiro, 2012	yes	uncertain	yes	yes	yes	yes	low
Miao, 2014	uncertain	uncertain	yes	yes	yes	no	moderate

^aFive or six domains with “yes” represents low risk of bias; three or four domains with “yes” represents moderate risk of bias; two or fewer domains with “yes” represents high risk of bias