Statistical Analyses
T2D
SECONDARY
These analyses were prespecified and performed according to the previously published statistical analysis plan (Linear mixed-effects models were used to assess between-group differences in changes in body components at baseline, 1 year, and 3 years of follow-up. Three-level linear mixed models were fitted with random intercepts at the recruiting center, cluster family, and individual participants, including an interaction term of study arm with time. Multivariable models were adjusted for sex, age, and baseline levels of smoking status, educational level, T2D, height, total leisure-time PA, sedentary behavior, total energy intake, and alcohol intake. To enable a direct comparison between body composition parameters, models were rerun with all outcome variables converted into In sensitivity analyses, the missing follow-up data on primary and secondary outcomes were handled using multivariate imputation with chained equations (Stata mi command), creating 100 imputations for each missing measurement. The imputation models included as factors age, sex, study arm, weight (waist when imputing visceral fat and its indicators), height, smoking habit, educational level, leisure-time PA, sedentary behavior, total energy intake, alcohol intake, T2D, recruiting center, and the baseline value of the imputed variable as factors.We also evaluated the potential effect of the PREDIMED-Plus intervention on dichotomous variables indicating at least 5% improvement in baseline body composition as an indicator of clinically relevant changes over follow-up. Given that the targets for clinically relevant changes in body composition are still unclear,Post hoc stratified analyses were conducted for primary outcomes by baseline categories of sex (men and women), age (<65 and ≥65 years), T2D prevalence (yes and no), and smoking habits (current or former smoker, or never smoker) using linear mixed-effects multivariable models. An interaction term between time, randomization arm of the trial, and each potential effect modifier was included in the models. We set the Statistical analyses were performed using Stata, version 17.0 (StataCorp LLC). All statistical tests were 2-sided, and the threshold of significance was set at .05, unless stated otherwise.