Offering prophylaxis for venous thromboembolism (VTE) should be based on an amalgam of risk, age, and life expectancy, according to a recent study.

Investigators built 1) a decision model decision-tree to follow patients for 3 months post-hospitalization, and 2) a lifetime Markov model with 3-month cycles. They tracked deep vein thromboses and pulmonary emboli; bleeding events; and heparin-induced thrombocytopenia, as well as recurrent VTE, post-thrombotic syndrome, and pulmonary hypertension. Patients received enoxaparin 40 mg day 1. Among the results:

• Prophylaxis was indicated for the typical inpatient with a VTE risk of ≥1% up to 3 months after hospitalization (assuming a willingness-to-pay threshold of $100,000/quality-adjusted life year).
• Prophylaxis was not indicated when the bleeding risk was >8.1%, the patient's age was >73.4 years, or the cost of enoxaparin exceeded $60/dose.
• If VTE risk was <0.26% or bleeding risk was >19%, prophylaxis risk outweighed benefits.