Cost-minimization analysis of simvastatin versus atorvastatin for maintenance therapy in patients with coronary or peripheral vascular disease

Abstract

Background: Previous health economic studies have demonstrated the cost-effectiveness of simvastatin in the treatment of coronary heart disease (CHD) based on clinical results of the Scandinavian Simvastatin Survival Study. A prior analysis evaluated the "cost of getting to goal," but ignored all costs after titration. However, when evaluating the cost-effectiveness of long-term therapies, it is important to consider the maintenance costs as well.

Objective: The purpose of this study was to evaluate the maintenance costs of treatment with simvastatin versus that of treatment with another more recently available statin, atorvastatin, in a European context.

Methods: We assessed the long-term maintenance cost of simvastatin versus atorvastatin in terms of the cost of reducing low-density lipoprotein cholesterol (LDL-C) levels to the recommended goals based on a previously published clinical trial in patients with CHD. The analysis focused on the patients in the original clinical trial who were randomized to treatment with simvastatin or atorvastatin. Patients began therapy with 10 mg of simvastatin or atorvastatin; the dose of study drug was titrated every 12 weeks up to 40 mg simvastatin or 80 mg atorvastatin, with the addition of up to 8 g/d of cholestyramine until a modified European Atherosclerosis Society LDL-C goal (<2.84 mmol/L) was reached. As there was no significant difference between the 2 groups in resource utilization for adverse events, only drug costs were included. The calculated average annual maintenance cost was based on the distribution of the final daily dosing regimens and the public drug prices for each regimen. Individual country analyses were conducted using each local currency.

Results: There was no significant difference between groups in the percentage of patients reaching their LDL-C goal over the study period (80% for simvastatin-treated pa- tients vs 89% for atorvastatin-treated patients, P = 0.135). However, the cost of maintaining a similar percentage of patients at their appropriate LDL-C levels was significantly lower in the simvastatin group compared with the atorvastatin group in 13 of the 17 countries assessed. In the remaining 4 countries, there was a cost advantage for simvastatin, but it did not reach statistical significance.

Conclusions: Across Europe there was a significant reduction in the cost of maintaining patients at their appropriate LDL-C levels with simvastatin versus atorvastatin. The results of this analysis, along with the proven clinical benefits of simvastatin, support the use of this drug as the treatment of choice in the secondary prevention of CHD.