Supplementary Table 2. Risk of bias assessment of the studies (n = 9) included in the systematic review.

	Randomization process	Deviations from intended interventions	Missing outcome data	Measurement of the outcome	Selection of the reported result	Overall bias
Assignment to intervention (the "intention-to-treat" effect)
Low risk of bias	50	100	100	87.5	100	50
Some concern	37.5	0	0	12.5	0	37.5
High risk of bias	0	0	0	0	0	0