Statistical methods
substance abuse, disability
The analysis was based on the “intention-to-treat” principle. Baseline variables were calculated as means for continuous variables (age, level of disability, etc.) and as proportions for categorical (education level, diagnosis, etc.) and dichotomous variables (sex, presence or absence of alcohol or substance abuse, etc.). To test for differences between the intervention group and control group at baseline, the chiPost hoc, we performed three additional analyses. First, we looked at within-group changes, comparing post-intervention assessments to baseline in the intervention group and the control group and using the paired t-test for statistical significance. Second, we examined differences in treatment effects when MA&R was delivered under “normal conditions” vs. during the COVID-19 pandemic. Participants were divided into two subsets: those who had completed post-intervention follow-up assessment before the COVID-19 lockdown, on the 12