Table 1.

Quality assessment criteria for RCTs

Authors	Quality assessment									Judgment on risk of bias
	Was the allocation sequence generated adequately?	Was the allocation of treatment adequately concealed	Did researchers rule out any unintended exposure that might bias results?	Were participants analysed within the groups they were originally assigned to?	Was the length of follow-up different between the groups	Were the outcome assessors blinded to the intervention or exposure status of participants?	Were the potential outcomes pre-specified by the researchers? Are all pre-specified outcomes reported?	If attrition was a concern were missing data handled appropriately?	Were outcomes assessed using valid and reliable measures across all study participants?
Blakeney et al. (2014)	Yes	No	Yes	Yes	No	No	Yes	Yes	Yes	Low risk
Choong et al. (2012)	Yes	No	Yes	Yes	No	No	Yes	Yes	Yes	Low risk
Huang et al. (2012)	Yes	No	Yes	Yes	No	No	Yes	Yes	Yes	Low risk
Lutzner et al. (2010)	Yes	No	Yes	Yes	No	No	Yes	Yes	Yes	Low risk
Gothesen et al. (2014)	Yes	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	Low risk

Assessed using AHRQ design specific scale (Stang 2010)