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Cardiovascular disease, atorvastatin, Markov model, cost-effectiveness, Canada
The TNT study compared high dose atorvastatin (80 mg) versus moderate atorvastatin (10 mg) treatment in 10,001 patients with stable coronary heart disease (CHD), over 4.9 years. Intensive lipid-lowering with atorvastatin (80 mg) reduced major cardiovascular events by 22%.
To assess the cost-effectiveness of intensive lipid-lowering versus moderate lipid lowering treatment from the perspective of the Canadian Ministries of Health.
A lifetime Markov model was developed to predict cardiovascular (CV) events, costs, survival, and quality-adjusted life years (QALYs) for CHD patients receiving 80 mg versus 10 mg of atorvastatin. Predictions were also made for 10- and 5-year horizons. Treatment-specific event risks were used until five years. Beyond year five, equivalent CV risks were assumed for all patients. Medical-care costs and post-event survival were estimated using Canadian data. Health utility scores were obtained from published studies. Benefits and costs were discounted 5% annually. Probabilistic and deterministic sensitivity analyses were performed.
Treatment with atorvastatin (80 mg) over a lifetime horizon resulted in increased costs (Can$16,542 vs. Can$15,365), survival (10.12 vs. 10.03 life years), and QALYs (7.71 vs. 7.61) per patient compared with atorvastatin (10 mg), yielding an incremental cost-effectiveness of Can$12,946 per life year gained and Can$11,969 per QALY. The incremental cost per QALY remained below Can$50,000 in 98.1% of 1000 simulations. Results were robust to variations in event hazard ratios, costs, health utility values, and discount rate.
Intensive atorvastatin (80 mg) treatment is predicted to be cost-effective versus atorvastatin (10 mg) for CHD patients in Canada.
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