Statistical analysis
INTERACTIONS
Descriptive statistics are given in percentages and numbers for categorical variables and means and standard deviation (SD) for continuous variables. Longitudinal associations between the two groups (the intervention and control group) and SMBQ scores were analysed using linear mixed models with random intercept in SPSS version 25 (IBM, Armonk, NY, USA). Age and gender were tested as possible confounders and the inclusion criterion was p < 0.25. Time was included as continuous variable (0, 3 and 6 months from inclusion in the study). Interactions between the groups and time were tested to evaluate whether the development over time was different in the two groups. Parameter estimates along with 95% confidence intervals (CIs) are presented as a measure of association.Post hoc analysis was done to understand the nature of the interaction effect. Independent-sample 