OBJECTIVES Examines the clinical and economic outcomes of this therapy modification in a community-based physician practice. Health care practitioners are commonly requested by insurers and patients to switch from their current statin to simvastatin for cost reasons. METHODS Medical record review via an electronic medical record from a community-based primary care office was performed on patients switched by the physician from another statin to simvastatin between January 1, 2002 to October 31, 2008. Patients were included if they had available lipid data pre- and post-switch. National Cholesterol Education Program (NCEP) risk categories were calculated and associated LDL cholesterol (LDL-C) goals assigned. Primary outcomes were changes in lipid fractions and LDL-C goal attainment, analyzed by paired t-tests and McNemar's test, respectively. Economic outcomes were modeled using current retail medication prices and Medicare costs for medical services. RESULTS A total of 48 patients were identified; atorvastatin was the most common pre-switch statin (31 patients). The cohort had a mean age of 64.6+12.6 years, was 60% female and 65% were primary prevention. Over 95% of patients were switched to an appropriate equipotent dose of simvastatin. Mean pre-and post-switch LDL-C levels were 104mg/dL and 103mg/dL, a non-significant reduction of 1.2+25.7mg/dL (p=0.754). Results for the other lipid fractions and in a subanalysis of atorvastatin switched-patients showed similar non-significant changes. A non-significant 4.1% increase in NCEP goal attainment between the pre-switch (68.8%) and post-switch (72.9%) time periods was observed (p=0.754). Modeled cost savings were estimated at $575/patient/year. CONCLUSIONS Previously treated statin patients switched to equipotent doses of simvastatin achieved similar LDL-C lowering and NCEP goal attainment within this community-based, primary care setting. These results show the potential for significant cost savings for the healthcare system when appropriate patients are switched using equipotent doses. Overall, these data support the approach that appropriate switching decisions should be made on a case-by-case basis.