Statistical analysis
SECONDARY
The efficacy population consisted of all participants randomized to study treatment (intention-to-treat). A per-protocol analysis was also performed. Categorical variables are expressed as frequencies and proportions; continuous variables are given as mean ± SD (variables normally distributed) or median and interquartile range (variables not normally distributed). Statistical differences in the primary outcome at 24 months were assessed by ANCOVA with treatment as fixed effect and baseline levels as covariates. The proportions of patients analyzed for secondary outcomes were assessed by contingency tables and χ