Statistical Analysis
weight loss
REGRESSION, SECONDARY
Analyses followed the intention-to-treat principle. Descriptive information was presented as means with SDs or medians with IQRs for continuous variables and as counts and frequencies for categorical variables. Total attendance rates were calculated for each participant and subsequently allocated to one of the following groups: low attendance (0 to 10 sessions), medium attendance (11 to 20 sessions), or high attendance (21 to 30 sessions). We categorized participants with all measurements available as complete cases, those missing 1 follow-up measurement as semicomplete, and those with no follow-up measurements as dropouts to see whether characteristics of dropouts and semicompleters differed from completers.First, differences between the lifestyle intervention and TAU groups in the primary and secondary outcomes between baseline and 3 (body weight only), 6, and 12 months were analyzed with linear mixed models.Additional analyses included crude and adjusted multivariable logistic regression analyses to assess proportion of weight changes (5% or more and 10% or more weight loss between baseline and 3, 6, and 12 months). Adjusted analyses included the following covariates: sex, primary mental health diagnosis, relationship (yes or no), and smoking status change between baseline and 3, 6, and 12 months (never smoked or started, stopped, or continued smoking). Furthermore, we performed a per-protocol analysis where we assessed whether intervention attendance (low attendance, medium attendance, and high attendance) influenced body weight change. Finally, additional post hoc analyses (not described in the protocolSignificance was set at 