Clinical Outcomes
depressive
REGRESSION
The primary analysis of clinical outcomes was an intention-to-treat (ITT) between-group comparison of MBCT-SH to CBT-SH at 16 weeks and 42 weeks using a linear mixed model with treatment group, time (16 weeks or 42 weeks), and a treatment group × time interaction as fixed factors and site and baseline PHQ-9 score as covariates. Participants were included as random effects. The ITT sample was composed of all participants and observed data, and individuals were analyzed as per randomization allocation. Secondary outcomes were estimated using linear mixed models and contrasts. Secondary per-protocol analyses were conducted for intervention completers (attending 3 or more PWP sessions). As a sensitivity check, missing data were assumed to be missing at random and dealt with using multiple imputation by chained equations and compared with observed-cases findings. Multilevel logistic regression compared treatment completion between groups controlling for center and baseline PHQ-9 score and are presented as adjusted odds ratios. Mediation analyses tested whether treatment completion mediated depressive symptom severity outcomes. Unplanned subgroup analyses were conducted to estimate PHQ-9 treatment effects at 16 weeks by sex, race and ethnicity, and medication use. Statistical analysis was conducted using Stata version 16 (StataCorp).