Care following acute myocardial infarction in the Veterans Administration Medical Centers: A comparison with Medicare

OBJECTIVE: To compare patients treated for acute myocardial infarction (AMI) in a Veterans Health Administration (VHA) facility to similar patients treated under Medicare. DATA SOURCES: Administrative data on 13,129 elderly male veterans hospitalized for AMI in a VHA facility between October 1, 1996, and September 30, 1999, and a matched set of male Medicare beneficiaries with AMI treated in a non-VHA facility during the same time period. STUDY DESIGN: We conducted a retrospective cohort study using propensity score methods to identify a matched set of male elderly AMI patients treated either in a VHA facility or in a non-VHA facility under Medicare. We compared the two groups of patients according to characteristics of the admitting hospital, distances traveled for care, the use of invasive procedures, and mortality. We assessed the robustness of our conclusions to biases arising from unmeasured confounders using sensitivity analyses. PRINCIPAL FINDINGS: VHA patients were significantly less likely than Medicare beneficiaries to be admitted to high-volume facilities (for example, 25 percent versus 46 percent in 1999, p