Table 5. Risk of bias judgments of the included controlled clinical trial.

Study	Bias due to confounding	Bias in the selection of the participants	Bias in the classification of intervention	Bias due to deviations from intended interventions	Bias due to missing data	Bias in the measurement of outcome	Bias in the selection of the reported results	Overall
Oland et al., 2010 [17]	Low risk: no confounding factors detected	Low risk: All participants who have been eligible for the target trial were included in the study	Low risk: Intervention status is well-defined	Low risk: No deviations from intended interventions were detected	Moderate risk: outcome data were not available for all participants. Missing data were not related to the intervention	Serious risk: No information about outcome assessors blinding and the results may be influenced by knowledge of the intervention received by study participants	Low risk: pre-defined outcomes mentioned in the methods section seemed to have been reported	Serious risk