Abstract 123: Patterns of Statin Use, Adherence, and Persistence among Patients in Working Age Patients With High-Risk Vascular Diseases: Findings from a Multi-Employer Claims Database

Abstract

BACKGROUND: Despite progress in treatment, high-risk vascular diseases (HRVD), including cerebrovascular disease (CVD), coronary artery disease with diabetes (CADD), acute coronary syndrome (ACS), and peripheral artery disease (PAD), account for approximately half of the rates of morbidity and mortality in the US. Limited research has been done to systematically study statin use patterns, adherence, and persistence for HRVD patients using real-world large claims databases. The objective was to examine statin use patterns, adherence, and persistence in patients with HRVD. METHODS: A retrospective cohort study was conducted using a large US administrative claims database for over 10 million beneficiaries annually from more than 100 self-insured Fortune 500 companies. HRVD patients (defined as patients with CVD, PAD, CADD, or a history of ACS [≥30 days through 365 days after discharge for ACS between 10/01/2008 and 09/30/2009]) aged 18 to 64 years, with minimum 12-month pre-index and 24-month post-index health plan eligibility, were identified for this study. Statin use, statin median/mean dose, percent of patients using maximal statin dose (defined as atorvastatin ≥80 mg and rosuvastatin ≥40 mg), and statin adherence (calculated using the medication possession ratio [MPR]) were measured at 6-month, 12-month, and 24-month follow-up periods. Persistence was assessed with survival analysis techniques using a ≥30-day gap to define a discontinuation. RESULTS: Among 516,863 identified HRVD patients, 38.7% used statins during the baseline period (PAD: 31.5%; CVD: 29.2%; CADD: 54.6%; ACS: 65.5%). The number increased to 40.6%, 43.3%, and 45.6% during the 6-month, 12-month, and 24-month follow-up periods, respectively, with greater increase of statin use in PAD and CVD patients (38.3%, 37.9%, respectively, during the 24-month follow-up period). Simvastatin (39.0%, 39.0%, 39.2%), atorvastatin (31.0%, 29.1%, 27.5%), and rosuvastatin (18.0%, 18.6%, 19.2%) were the most commonly used statins with 8.1%, 7.4%, and 7.3% of patients using maximum statin doses at 6-month, 12-month, and 24-month follow-up periods, respectively. There appeared to be little changes in statin doses during the 24-month follow-up period (mean/median dose: simvastatin 44.1/40 mg, 44.3/40 mg, 44.7/40 mg; atorvastatin 36.7/30 mg, 37.2/30 mg, 37.6/40 mg; rosuvastatin 17.2/10 mg, 17.4/10 mg, 17.9/10 mg). The mean/median MPR was 0.64/0.66, 0.60/0.66, and 0.49/0.49 among HRVD patients who used a statin with only 13.8%, 14.0%, and 10.9% of patients adherent (MPR≥80%) to their statin therapy during the 6-month, 12-month, and 24-month follow-up periods, respectively. The mean time to statin discontinuation was 357 days during the 24-month follow-up period. CONCLUSIONS: Nonadherence to statins is common for patients with HRVD, and the patterns of statin adherence persist over time with little titration in doses.