In men without a history of cardiovascular disease, is low-dose aspirin, a statin, or both drugs cost-effective in preventing cardiovascular events?
Compared with no treatment, aspirin is less costly and more effective for preventing CHD events in middle-aged men whose 10-year risk for CHD is 7.5% or higher. The addition of a statin to aspirin therapy becomes more cost-effective when the patient’s 10-year CHD risk before treatment is higher than 10%
Pignone M, Earnshaw S, Tice JA, Pletcher MJ. Aspirin, statins, or both drugs for the primary prevention of coronary heart disease events in men: A cost-utility analysis. Ann Intern Med 2006;144:326-36.
Although both aspirin and statin drugs, separately, are effective for preventing a first CHD event, there is no direct evidence that the combination is more effective than either alone. The researchers conducting this analysis determined the cost-effectiveness of the combination from the perspective of a third-party payer and we can use this analysis to understand the relative benefits of the 2 treatments. The researchers started with a base-case scenario of a 45-year-old man with a 10-year risk of CHD of 7.5% treated with aspirin, statin therapy, both, or neither for 10 years. The outcome was the development of a CHD event — stroke, myocardial infarction, or death — over the 10 years. The Markov model used in this analysis also assumed that all patients would be treated with both drugs after 10 years and then estimated their life-time cost-utility ratio. They also considered the major risks of treatment, gastrointestinal bleeding, and myopathy-related death, derived from results of clinical trials.
For men at low risk, lifetime aspirin therapy increases their lifespan an average of 3 days (adjusted for quality of those days, or “quality-adjusted days”). Men at moderate (7.5%) risk gained an average 17 quality-adjusted days, and men at moderate to high risk (10%) gained 24 quality-adjusted days. When statin was theoretically added to aspirin treatment, the average increase in lifespan was 13 days for low-risk men (an additional 10 days over aspirin alone), 35 days for moderate risk (an additional 18 days), and 45 days (an additional 21 days) for men at moderate to high risk. In men with low risk, the cost per quality-adjusted life-year is a very reasonable $9800 US for aspirin alone but $164,700 US for the combination. At moderate risk, combination therapy is a reasonable $56,200 (though the range, depending on the sensitivity analysis, was $26,100 to $246,276). At moderate to high risk the cost per quality-adjusted life-year was $42,500 (range = $20,600 – $188,000).