 I. Power calculation Power calculation was done in order to estimate the minimum number of patients to be included in the study. A default value of 0.80 was chosen. Calculations are based on the assumption of the minimum relevant clinical difference between the two types of treatment in terms of number of days of sick leave. Patients will be randomized in two groups of equal size. Based on similar studies the investigators expect normalparametric distribution of the data with standard deviation of 6 and mean difference of 3 between the two groups. Based on these assumptions a minimum of 64 patients should be included in each group to reject the null hypothesis that there is no difference in the number of sick leave days. Significance level is set at 0.05. 