Development of a Clinical Prediction Rule for Risk Stratification of Recurrent Venous Thromboembolism in Patients with Cancer: Associated Venous Thromboembolism
Background—Long-term low molecular weight heparin (LMWH) is the current standard for treatment of venous thromboembolism (VTE) in cancer patients. Whether treatment strategies should vary according to individual risk of VTE recurrence remains unknown. We performed a retrospective cohort study and a validation study in patients with cancer-associated VTE to derive a clinical prediction rule that stratifies VTE recurrence risk.
Methods and Results—The cohort study of 543 patients determined the model with the best classification performance included 4 independent predictors (sex, primary tumor site, stage and prior VTE.) with 100% sensitivity, a wide separation of recurrence rates, 98.1% negative predictive value and a negative likelihood ratio of 0.16. In this model, the score sum ranged between -3 and +3 score points. Patients with a score ≤ 0 had low risk (≤4.5%) for recurrence and patients with a score above 1 had a high risk (≥19%) for VTE recurrence. Subsequently, we applied and validated the rule in an independent set of 819 patients from 2 randomized controlled trials comparing LMWH to coumarin treatment in cancer patients.
Conclusions—By identifying VTE recurrence risk in cancer patients with VTE we may be able to tailor treatment, improving clinical outcomes while minimizing costs.
- Received July 4, 2011.
- Accepted May 2, 2012.
- Copyright © 2012, American Heart Association, Inc. All rights reserved. Unauthorized use prohibited