Statistical analysis
The primary analyses were carried out on the intention-to-treat (ITT) sample, prespecified as all randomized participants for whom baseline data were available for the primary outcome. All analyses were then run with the per protocol (PP) sample, which was pre-specified as all randomized patients who attended 50% or more of the therapy sessions provided. We fitted linear mixed models (LMMs) with three hierarchical levels: time of measurement on level 1, nested within patient on level 2, and nested within study centers on level 3. The model included time (from Standardized effect sizes (Cohen’s 