Long-term Cost-effectiveness of Statin Treatment for Primary Prevention of Cardiovascular Disease in the Elderly.

Abstract

This study aimed to evaluate the cost-effectiveness of statins for primary prevention of stroke and myocardial infarction (MI) in the elderly in Singapore. A Markov model was developed to investigate the lifetime costs, quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs) of statin treatment in those aged 65 years and older without a history of stroke or MI from the perspective of Singapore's healthcare system, using elderly-specific clinical data and local costs from hospital databases. A lifetime horizon was used and all costs and health outcomes were discounted at 3% annually. In the base-case analysis, statin treatment prevented an additional four strokes and eight MIs among 1,000 "healthy" elderly individuals compared with no treatment. Statin treatment resulted in a QALY gain of 0.26 and additional costs of SGD 11,314 per person, yielding an ICER of SGD 43,925 (USD 33,495) per QALY gained. The results were sensitive to statin effectiveness, particularly statins' effect on all-cause mortality, and cost of statin medication. Probabilistic sensitivity analysis demonstrated that the probability of statin treatment being cost-effective was 72% at a willingness-to-pay threshold of SGD 65,000 (USD 49,546) per QALY gained. Shortening the time horizon from lifetime to 10 years (simulating limited life expectancy) considerably increased the ICER to SGD 291,313 (USD 167,171) per QALY. Female gender and younger age were also associated with higher ICERs owing to a lower baseline risk of cardiovascular disease (CVD) and higher costs to manage events in these subgroups. Statin treatment for the primary prevention of CVD in the elderly was cost-effective. However, treatment warrants re-evaluation when the prognosis of the individual is considered less than ten years; other goals may take precedence over CVD prevention.