Effectiveness of rosuvastatin versus atorvastatin in reducing lipid levels and achieving low-density-lipoprotein cholesterol goals in a usual care setting

Abstract

Purpose: The effectiveness of rosuvastatin versus atorvastatin in reducing lipid levels and achieving low-density-lipoprotein (LDL) cholesterol goals in patients treated in a usual care setting was studied.

Methods: Electronic medical and pharmacy administrative claims from a western U.S. health plan with approximately 8 million covered members were extracted and used in this retrospective, longitudinal cohort study. Patients age 18 years or older who were newly initiated on rosuvastatin or atorvastatin between August 1, 2003, and June 30, 2004, were included. Propensity-score matching on baseline characteristics was used to minimize selection bias between groups. Administrative claims and medical records were used to assign patients a cardiovascular risk status and corresponding LDL cholesterol goal using guidelines from the National Cholesterol Education Program (NCEP). Changes in lipid levels and attainment rates of goal LDL cholesterol levels were estimated after accounting for baseline covariates using regression techniques.

Results: A total of 453 patients met the study criteria. The mean dose of rosuvastatin was 11 mg compared with 15 mg for atorvastatin. After adjusting for baseline differences between groups, patients receiving rosuvastatin had significantly greater mean percent reductions in LDL cholesterol, total cholesterol, and non-high-density-lipoprotein (non-HDL) cholesterol than did patients receiving atorvastatin (p < 0.001 for all comparisons). No significant differences were found in HDL cholesterol and triglyceride levels between groups. Attainment rates for NCEP LDL cholesterol goals were significantly higher in patients receiving rosuvastatin.

Conclusion: Patients treated in a usual care setting with rosuvastatin had significantly greater reductions in LDL cholesterol, non-HDL cholesterol, and total cholesterol levels compared with those receiving atorvastatin. Patients receiving rosuvastatin were more likely to attain NCEP LDL cholesterol goals compared with patients treated with atorvastatin.