Missing data handling
Missing data for all covariates were handled with an approach that considers the time-dependence of the covariates in the imputation model [Robust variances were estimated by bootstrap (1000 iterations) to account for the fact that observations of patients have been duplicated in the analysis. Significance level was set at 0.05. Analyses were performed using R software, version 4.1.2 (R Core Team 2021, 