Table 3.

Quality appraisal for included studies

Author (Year)	Appropriate Randomisation Technique	Allocation concealment	Dropout rate <20 %	Potential confounders properly accounted for	Were eligibility clear
Van Gaalen [30]	No	No	Yes	Yes	Yes
Van der Meer [31–33]
Hashimoto [34]	No	No	Yes	Yes	Yes
Bender [35]	Yes	Yes	Yes	No	Yes
Liu [36]	Not clear	Not clear	No	No	Yes
Rasmusen [37]	Yes	Yes	Yes	No	Yes