Abstract 856: Impact of Availability of Generic Simvastatin on Low-density Lipoprotein Cholesterol Goal Attainment
The availability of generic simvastatin has prompted substantial changes in formulary recommendations. The goal of this retrospective, observational study was to examine the impact of switches to simvastatin on low density lipoprotein cholesterol (LDL-C) goal attainment among coronary heart disease (CHD)/CHD risk equivalent patients in a large national managed care claims database. We identified 1,607,341 patients initially treated with ezetimibe/simvastatin fixed dose combination (E/S) (N=302,257), rosuvastatin (N=277,757), or atorvastatin (N=1,027,327) who were either continued on their initial therapy or switched to simvastatin between 9/1/2004 and 10/31/08. A total of 49,633 patients switched to simvastatin in the observation period (14,157 E/S, 4,234 rosuvastatin, and 31,242 atorvastatin). Patients were excluded if age <18; use of any other concomitant lipid lowering therapy; discontinuation of pre/post index therapy (>90 days gap in refill); no LDL-C test at baseline/follow-up; not CHD/CHD risk equivalent at baseline. After inclusion/exclusion criteria were applied, there were 18,219 eligible patients. Mean follow-up duration was 4.3 months. Percent change from baseline LDL-C value was compared between switchers and nonswitchers for each baseline therapy using ANCOVA. Logistic regression was used to model LDL-C goal attainment rates (<100 mg/dL & <70 mg/dL) at follow-up for each baseline therapy separately. All analyses were adjusted for age, gender, and baseline medication potency while the logistic regressions also adjusted for baseline goal attainment. Switchers had higher LDL-C values and lower goal attainment rates at follow-up compared to nonswitchers.