Table 1.

Risk of bias assessment using the CBRG criteria.

	Gil et al. (2008) [3]	Moon et al. (2010) [4]	Usubiaga et al. (1967) [5]
Was the method of randomization adequate?	Yes	Yes	No
Was the treatment allocation concealed?	No	No	No
Was the patient blinded to the intervention?	No	No	No
Was the care provider blinded to the intervention?	No	No	No
Was the outcome assessor blinded to the intervention?	No	Yes	No
Was the drop-out rate described and acceptable?	Yes	Yes	Yes
Were all randomized participants analyzed in the group to which they were allocated?	Yes	Yes	Yes
Are reports of the study free of suggestion of selective outcome reporting?	Yes	Yes	Yes
Were the groups similar at baseline regarding the most important prognostic indicators?	No	Unsure	No
Were cointerventions avoided or similar?	Yes	Yes	Unsure
Was the compliance acceptable in all groups?	Yes	Yes	Yes
Was the timing of the outcome assessment similar in all groups?	Yes	Yes	Yes