Validation of a score for predicting fatal bleeding in patients receiving anticoagulation for venous thromboembolism

The only available score to assess the risk for fatal bleeding in patients with venous thromboembolism (VTE) has not been validated yet.

We used the RIETE database to validate the risk-score for fatal bleeding within the first 3 months of anticoagulation in a new cohort of patients recruited after the end of the former study. Accuracy was measured using the ROC curve analysis.

As of December 2011, 39,284 patients were recruited in RIETE. Of these, 15,206 had not been included in the former study, and were considered to validate the score. Within the first 3 months of anticoagulation, 52 patients (0.34%; 95% CI: 0.27-0.45) died of bleeding. Patients with a risk score of <1.5 points (64.1% of the cohort) had a 0.10% rate of fatal bleeding, those with a score of 1.5-4.0 (33.6%) a rate of 0.72%, and those with a score of >4 points had a rate of 1.44%. The c-statistic for fatal bleeding was 0.775 (95% CI 0.720-0.830). The score performed better for predicting gastrointestinal (c-statistic, 0.869; 95% CI: 0.810-0.928) than intracranial (c-statistic, 0.687; 95% CI: 0.568-0.806) fatal bleeding. The score value with highest combined sensitivity and specificity was 1.75. The risk for fatal bleeding was significantly increased (odds ratio: 7.6; 95% CI 3.7-16.2) above this cut-off value.

The accuracy of the score in this validation cohort was similar to the accuracy found in the index study. Interestingly, it performed better for predicting gastrointestinal than intracranial fatal bleeding.