Disparities in combination drug therapy use in older adults with coronary heart disease: a cross-sectional time-series in a nationally representative US sample

Abstract

BACKGROUND: Despite evidence of effective combination drug therapy for secondary prevention of coronary heart disease (CHD), older adults with this condition remain undertreated. OBJECTIVE: To describe time trends (1992-2003) in the adoption of combination cardiac drug therapies (beta-blockers [beta-adrenoceptor antagonists], ACE inhibitors or angiotensin II type 1 receptor antagonists [angiotensin receptor blockers; ARBs], and lipid-lowering agents) among older adults in the US with CHD and to identify factors associated with not using combination therapy. METHODS: The study took the form of a cross-sectional time-series. The study population consisted of a nationally representative sample of adults aged >or=65 years with CHD (unweighted n = 6331; weighted n = 20.1 million) included in the 1992-2003 Medicare Current Beneficiary Survey. The outcome measure was low-intensity cardiac pharmacotherapy (no drug or single drug therapy with beta-blockers, ACE inhibitors/ARBs or lipid-lowering agents) compared with combination therapy (>or=2 cardiac drugs) for secondary CHD prevention. RESULTS: The use of combination drug therapy in older adults with CHD increased 9-fold during the study period (from 6% in 1992 to 54% in 2003). Adjusted analyses demonstrate that suboptimal drug therapy was independently associated with advanced age (relative risk [RR] 1.18; 95% CI 1.14, 1.23) for patients aged >or=85 years versus patients aged 65-74 years, and with being non-Hispanic Black (RR 1.05; 95% CI 1.01, 1.10) or Hispanic (RR 1.13; 95% CI 1.06, 1.21) versus being non-Hispanic White. CONCLUSIONS: Combination drug therapy use for secondary CHD prevention increased in older US adults over the last decade, but improvements were not uniform. The oldest-old, non-Hispanic Blacks and Hispanics experienced slower adoption of optimal medical therapy to improve their long-term prognosis for CHD.