Economic evaluation of high-dose (80 mg/day) atorvastatin treatment compared with standard-dose (20 mg/day to 40 mg/day) simvastatin treatment in Canada based on the Incremental Decrease in End-Points Through Aggressive Lipid-Lowering (IDEAL) trial

Abstract

The Incremental Decrease in End-Points Through Aggressive Lipid-Lowering (IDEAL) trial demonstrated incremental cardiovascular benefit of treatment with high-dose atorvastatin (80 mg/ day) versus standard-dose simvastatin (20 mg/day to 40 mg/day) in 8888 patients with a previous myocardial infarction (MI) over a median follow-up period of 4.8 years. To assess the cost-effectiveness of high-dose atorvastatin versus standard-dose simvastatin treatment in patients with a history of MI from a Canadian societal perspective. In a within-trial analysis, end point-related events, resources used and productivity losses occurring during the IDEAL trial were aggregated by treatment arm on an intention-to-treat basis to calculate the incremental cost per event avoided. Additionally, quality-adjusted survival was projected using a lifetime Markov model. Transition probabilities, workdays lost, use of study medication and cardiovascular hospitalization rates were based on IDEAL trial data. Hospitalization, study medication and productivity costs were included. Probabilistic and deterministic sensitivity analyses were performed. Compared with standard-dose simvastatin, atorvastatin 80 mg led to 0.099 fewer events per patient and cost savings over 4.8 years of treatment. Over a lifetime horizon, atorvastatin 80 mg led to 0.023 qualityadjusted life years (QALYs) gained per patient at an incremental cost of $26,795/QALY gained. The incremental cost-effectiveness ratio remained below $50,000/QALY in 78% of 1000 simulations. Exclusion of indirect costs resulted in an incremental cost-effectiveness ratio of $38,834/QALY. Results were relatively sensitive to baseline age, but robust with respect to sex, baseline low-density lipoprotein cholesterol levels, diabetes status and hospitalization costs. From a Canadian societal perspective, high-dose atorvastatin is cost-effective compared with standard-dose simvastatin in patients with a previous MI.