An Economic Evaluation of Atorvastatin for Primary Prevention of??Cardiovascular Events in Type??2??Diabetes

Abstract

The CARDS trial, a multicentre, randomized, controlled trial, found that atorvastatin 10 mg/day for patients with type 2 diabetes mellitus and normal low-density lipoprotein (LDL)-cholesterol significantly reduced cardiovascular (CV) events, including stroke. We estimated the cost effectiveness of atorvastatin as primary prevention against CV disease from the short-term and lifetime US payer perspectives. We constructed a decision analytic (Markov) model to evaluate long-term costs and outcomes for atorvastatin 10 mg/day versus no HMG-CoA reductase inhibitor (statin) therapy for patients with type 2 diabetes and no history of a CV event. CV event rates and survival were based on risk equations calibrated to CARDS and applied to a US type 2 diabetes population; the atorvastatin effect on CV events was based on hazard ratios from CARDS; direct medical care costs were based on US treatment patterns and published costs analyses of patients with diabetes. Costs were valued in $US, year 2005 values; costs and benefits were discounted at 3% per annum. Within the time horizon of the trial (5 years), the cost effectiveness of atorvastatin was $US137 276 per QALY. At 10 years, the incremental cost per QALY improved to $US3640 per QALY. At 25 years, overall costs were lower and QALYs higher in the atorvastatin arm. Costs of managing CV events were lower after 5 years for patients treated with atorvastatin. For patients with type 2 diabetes and one additional risk factor for CV disease, normal LDL-cholesterol and no history of a CV event, primary prevention with atorvastatin appears to be cost saving and improve outcomes over 25 years, although it is costly from a short-term US payer perspective. From both a medical and an economic viewpoint, primary prevention is desirable in this patient population.