Risk of cardiovascular events and death--does insurance matter?

Abstract

BACKGROUND: Many Americans lack health insurance. Despite good evidence that lack of insurance compromises access to care, few prospective studies examine its relationship to health outcomes. OBJECTIVE: To determine the relationship between insurance and cardiovascular outcomes and the relationship between insurance and selected process measures. DESIGN AND PARTICIPANTS: We used data from 15,792 participants in the Atherosclerosis Risk in Communities Study, a prospective cohort study. Participants were enrolled in 1987-1989 and returned for follow-up visits every 3 years, for a total of 4 visits. MAIN OUTCOME MEASURES: We estimated the hazard of myocardial infarction, stroke, and death associated with insurance status using Cox proportional hazard modeling. We used generalized estimating equations to examine the association between insurance status and risk of (1) reporting no routine physical examinations, (2) being unaware of a personal cardiovascular risk condition, and (3) inadequate control of cardiovascular risk conditions. RESULTS: Persons without insurance had higher rates of stroke (adjusted hazard ratio, 95% CI 1.22-2.22) and death (adjusted hazard ratio 1.26, 95% CI 1.03-1.53), but not myocardial infarction, than those who were insured. The uninsured were less likely to report routine physical examinations (adjusted risk ratio 1.13, 95% CI 1.08-1.18); more likely to be unaware of hypertension (adjusted risk ratio 1.12, 95% CI 1.00-1.25) and hyperlipidemia (adjusted risk ratio 1.11, 95% CI 1.03-1.19); and more likely to have poor blood pressure control (adjusted risk ratio 1.23, 95% CI 1.08-1.39). CONCLUSIONS: Lack of health insurance is associated with increased rates of stroke and death and with less awareness and control of cardiovascular risk conditions. Health insurance may improve cardiovascular risk factor awareness, control and outcomes.