Correlation of STOP score with predicted operative morbidity and mortality. The STOP score led to the excellent characterization of operative morbidity status and highly correlated with the observed outcome (R2, 99.6; 95% CI, 99.6–99.7; p < .001). It also highly correlated with the observed outcome (R2, 87.7; 95% CI, 86.3–89.0; p < .001). CI, confidence interval; OR, odds ratio; STOP, STratification risk analysis in OPerative management of drug-associated IE