Abstract 112: Adherence and Persistence with Statins in Patients with ASCVD

Abstract

Introduction: The benefits of lipid lowering therapy (LLT) include reductions in fatal CV disease, CHD and all-cause mortality. Adherence to LLT is critical for patient benefit. Several studies studies have shown high rates of LLT discontinuation and poor persistence but little is known about adherence and persistence with LLT in patients with artherosclerotic cardiovascular disease (ASCVD). Hypothesis: This study examined adherence and persistence to LLT in patients with ASCVD initiating statin therapy. Methods: This retrospective claims-based study used medical, pharmacy, laboratory and enrollment data from a large US health plan. Patients had commercial or Medicare Advantage Part D (MAPD) coverage and were identified from 1/1/07 to 12/31/12 and were followed for three years, disenrollment or 12/31/13 whichever occurred first. The index date was the date of first statin and/or ezetimibe use. Treatment modifications included switching, dose escalation or reduction, augmentation, and discontinuation. ASCVD patients were identified as having a myocardial infarction, stroke, revascularization (coronary artery bypass graft or percutaneous coronary intervention), unstable angina, or peripheral artery disease in the 12 months prior to the index statin. The time to first treatment modification and the proportion of patients who discontinued therapy were examined. Adherence was examined using a medication possession ratio (MPR) and persistence via % discontinuing medication. Results: The sample included 91,740 patients with ASCVD (mean age 64.9 years, 57.4% male, 37.7% MAPD). The mean time to first treatment modification, including discontinuation, was 351.7 days (SD=334.4; median=216.0). Over the course of treatment, 23.7% remained on index therapy, 34.3% had a treatment modification and 42.0% of patients discontinued therapy. However, 29.6% restarted therapy sometime in the study follow-up period. The mean MPR while on therapy was 0.89 (SD=0.13, median =0.95) in the overall sample and 0.92 (SD=0.12, median =0.97) in patients with ASCVD. The proportion of patients with a MPR ≥0.80 was 79.0% in the overall cohort and 84.6% in patients with ASCVD. Conclusions: While patients remained on their first statin (or ezetimibe) therapy for a substantial period of time, a large proportion of patients eventually discontinue therapy. Overall, adherence was high, indicating that ASCVD patients are compliant with their LLT. Interventions and new treatments to improve lipid lowering therapy seem necessary in patients with ASCVD.