Factors associated with statin selection among privately insured commercial and Medicare patients.

OBJECTIVES: Given the availability of several statins in the United States, it is important to understand patient characteristics associated with their initiation. We analyzed demographic and clinical factors associated with statin selection among new statin users.

METHODS: This retrospective cohort study examined factors associated with statin selection among patients newly initiated on therapy between 1/1/2007 and 12/31/2007. Commercial and Medicare patient cohorts were evaluated separately and comparisons were made between pravastatin (PS) and other statins including simvastatin (SS), atorvastatin (AS), or rosuvastatin (RS). Multiple logistic regression models were employed to assess factors associated with PS initiation versus other statins.

RESULTS: In commercially insured patients, patients initiating PS were more likely to be older, female, and have diabetes mellitus, liver dysfunction, human immunodeficiency virus (HIV) infection, or hypertension and use calcium channel blockers, protease inhibitors, or additional lipid-modifying agents (p < 0.01 for each comparison). In Medicare-age patients, a higher percentage of PS initiators were aged 75-85, female, had atrial fibrillation, and were prescribed warfarin or triazole antifungals (p < 0.01 for each comparison). Presence of atrial fibrillation or HIV infection, or use of calcium channel blockers or additional lipid-modifying agents was associated with PS initiation compared with AS and SS. Use of warfarin was significantly associated with initiating PS compared with SS, AS, and RS in Medicare-age patients.

CONCLUSION: Older age and female gender were associated with PS initiation. In addition, selected comorbidities and use of certain medications including warfarin or protease inhibitors were associated with PS initiation, which may reflect the tolerability of PS and its reduced risk of significant drug-drug interactions for certain patients. Because this study is a retrospective analysis of US healthcare claims, the findings are limited to only those factors captured within claims data and may not be generalizable to all patient populations in which statin therapy is initiated.