Supplemental insurance and use of effective cardiovascular drugs among elderly Medicare beneficiaries with coronary heart disease

Context: Cost-sharing in US prescription drug coverage plans for elderly persons varies widely. Evaluation of prescription drug use among elderly persons by type of health insurance could provide useful information for designing a Medicare drug program. Objective: To determine use of effective cardiovascular drugs among elderly persons with coronary heart disease (CHD) by type of health insurance. Design, Setting, and Patients: Cross-sectional evaluation of 1908 community-dwelling adults, aged 66 years or older, with a history of CHD or myocardial infarction from the 1997 Medicare Current Beneficiary Survey, a nationally representative sample of Medicare beneficiaries. Main Outcome Measures: Use of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins), β-blockers, and nitrates, and out-of-pocket expenditures for prescription drugs, stratified by type of health insurance: Medicare without drug coverage (Medicare only or self-purchased supplemental insurance) or with drug coverage (Medicaid, other public program, Medigap, health maintenance organization, or employer-sponsored plan). Results: Statin use ranged from 4.1% in Medicare patients with no drug coverage to 27.4% in patients with employer-sponsored drug coverage (P<.001). Less variation between these 2 types occurred for β-blockers (20.7% vs 36.1%; P=.003) and nitrates (20.4% vs 38.0%; P=.005). In multivariate analyses, statin use remained significantly lower for patients with Medicare only (odds ratio [OR], 0.16; 95% confidence interval [CI], 0.05-0.49) and β-blocker use was lower for Medicaid patients (OR, 0.55; 95% CI, 0.34-0.88) vs those with employer-sponsored coverage. Nitrate use occurred less frequently in persons lacking drug coverage (patients with Medicare only, P=.049; patients with supplemental insurance without drug coverage, P=.03). Patients with Medicare only spent a much larger fraction of income on prescription drugs compared with those with employer-sponsored drug coverage (7.9% vs 1.7%; adjusted P<.001). Conclusion: Elderly Medicare beneficiaries with CHD who lack drug coverage have disproportionately large drug expenditures and lower use rates of statins, a class of relatively expensive drugs that improve survival.