Abstract 77: Statin Adherence and Persistence Among Japanese Patients With High Risk Vascular Disease: A Japan Claims Database Analysis

Abstract

BACKGROUND: High risk vascular disease (HRVD defined as cerebrovascular disease [CVD], coronary artery disease with diabetes [CADD], history of acute coronary syndrome [ACS], or peripheral artery disease [PAD]) is among the biggest health problems affecting Japanese, with CVD and coronary artery disease (CAD) being the 2nd and 3rd most common causes of death. Despite proven efficacy of statins in reducing CV mortality, limited research is available to systematically study statin adherence and persistence for HRVD patients in Japan. OBJECTIVE: Examine statin adherence and persistence in HRVD patients. METHOD: A retrospective cohort study was conducted using the Japan Medical Data Center (JMDC) database, a large Japanese administrative claims database with 10 insurance societies (payers), and integrated inpatient, outpatient, and pharmacy claims of approximately 0.8 million covered lives from 2006-2011. Patients > 18 years with HRVD (CVD, PAD, CADD or history of ACS [≥30days through 365 days after discharge for ACS]) between 01/01/2008 to 12/31/2009, were identified for this study with minimum 12-month pre- and 24-month post-index insurance eligibility. Statin use was measured during the 12-month baseline period and the 24-month follow-up period. The date of the first HRVD claim(s) satisfying the above inclusion criteria was defined as the index date. Statin use was examined for the overall HRVD group as well as subgroups of patients with CVD only, PAD only, CADD only, history of ACS only, and patients with multiple HRVDs. Statin adherence, calculated using the medication possession ratio [MPR], and statin persistence, assessed with survival analysis techniques using a ≥30-day gap to define discontinuation, were measured in the 24-month follow-up period for the overall HRVD patient group. RESULTS: There were 10,400 HRVD patients identified in the JMDC database. Mean age was 52.8 and 57.1% were male. Statin use during the baseline period showed 12.1% of HRVD patients taking statins (CVD only: 10.2%; PAD only: 9.6%; CADD only: 14.6%; history of ACS only: 46.7%; CADD and a history of ACS: 48.3%; 2 affected artery beds: 17.8%; 3 affected artery beds: 19.5%). Statin use increased to 32.9% during the 24-month follow-up period (CVD only: 27.6%; PAD only: 26.6%; CADD only: 45.1%; history of ACS only: 54.4%; CADD and a history of ACS: 58.3%; 2 affected artery beds: 49.3%; 3 affected artery beds: 45.5%). For Japanese HRVD patients who used a statin, mean/median MPR was 0.89/0.94 and 82.1% of statin users were adherent (MPR ≥80%) to their statin therapy during the 24-month follow up period. The median time to statin discontinuation was 679 days during the 24-month follow up period. CONCLUSION: Statin use after HRVD diagnosis was modest and highest in ACS patients and patients with multiple affected vascular beds. Statin adherence was high among patients with HRVD in Japan.