Validation of propensity score matching. (Left) The density of propensity scores for cases in the vascular complications group and the no vascular complications group before and after matching. The overlapping area represents patients with similar propensity scores available for close matches. (Right) ‘Love Plot’ illustrates the covariate balance created in the propensity score-matched sample. The standardized mean differences comparing covariates between the vascular complications and no vascular complications groups are shown both in the original sample and after propensity score matching. While there were relevant differences (>20%) in covariates between both groups in the original sample, after matching all are close to zero, indicating a balance between cases in the vascular complications and no vascular complications groups for all relevant covariates.