Economic Evaluation of Atorvastatin for Prevention of Recurrent Stroke Based on the SPARCL Trial

Objectives: This study evaluated the economic implications of results obtained by the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) trial. Methods: To enable long-term projection of the trial results, a discrete event simulation of the course of clinical care after a recent stroke or transient ischemic attack (TIA) was developed. It generates pairs of identical patients; both receive usual care, one receives atorvastatin in addition. Their clinical course is simulated based on their risk of stroke, cardiovascular events, and case fatality rates taken from SPARCL, life expectancy from Saskatchewan Health data, and utility weights from literature. Costs, from a US health-care payer perspective in 2005 US dollars, were estimated for a within-trial 5-year period; survival and quality-adjusted life-years (QALYs) were extrapolated over a patient's lifetime; all discounted at 3%/year. Results: The prevention of stroke, coronary, and other cardiovascular events expected with atorvastatin translates to mean gains of 0.155 life-years gained and 0.172 QALYs per patient over their lifetime. Reducing associated medical costs ($8405 vs. $11,237) but increasing drug costs ($13,984 vs. $8752) results in net $2400/patient, or $13,916/QALY gained. Probabilistic sensitivity analysis indicates no simulations yield ratios above $50,000/QALY. Conclusion: Prescribing atorvastatin for patients with prior stroke or TIA is expected to provide health benefits at an acceptable cost in the United States.