Socioeconomic status and outcome following acute myocardial infarction in elderly patients

Abstract

Background: Although the Medicare entitlement provides universal hospital care coverage for elderly Americans, disparities in care processes after acute myocardial infarction still exist. Whether these disparities account for increased mortality among elderly poor patients is not known.

Methods: To determine the association between socioeconomic status and acute myocardial infarction treatment, procedure use, and 30-day and 1-year mortality, we analyzed data from 132 130 elderly Medicare beneficiaries hospitalized for acute myocardial infarction between January 1994 and February 1996. Patients were categorized into 10 groups of increasing income using the median income of the ZIP code of residence.

Results: The highest-income beneficiaries received higher rates of evidence-based medical therapy and had lower adjusted 30-day and 1-year mortality rates compared with the middle-income beneficiaries (30-day relative risk, 0.89 [95% confidence interval, 0.85-0.94]; and 1-year relative risk, 0.92 [95% confidence interval, 0.88-0.97]). Conversely, the lowest-income beneficiaries received lower rates of evidence-based medical treatment and had higher adjusted 30-day and 1-year mortality rates relative to the middle-income beneficiaries (30-day relative risk, 1.09 [95% confidence interval, 1.04-1.13]; and 1-year relative risk, 1.05 [95% confidence interval, 1.00-1.10]). Coronary revascularization rates were similar among income groups.

Conclusions: Despite the Medicare entitlement, there remain significant socioeconomic disparities in medical treatment and mortality among elderly patients following acute myocardial infarction. Income was independently associated with short- and long-term mortality. More research is required to determine the mechanisms contributing to adverse outcomes among poor elderly patients and to determine whether expansion of Medicare coverage will alleviate these disparities.