Cost-effectiveness of intensive lipid lowering therapy with 80 mg of atorvastatin, versus 10 mg of atorvastatin, for secondary prevention of cardiovascular disease in Canada.

BACKGROUND

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%.

OBJECTIVES

To assess the cost-effectiveness of intensive lipid-lowering versus moderate lipid lowering treatment from the perspective of the Canadian Ministries of Health.

METHODS

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.

RESULTS

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.

CONCLUSION

Intensive atorvastatin (80 mg) treatment is predicted to be cost-effective versus atorvastatin (10 mg) for CHD patients in Canada.