Geographic Variation in Trends and Disparities in Acute Myocardial Infarction Hospitalization and Mortality by Income Levels, 1999-2013

Abstract

Importance Over the last decade, acute myocardial infarction (AMI) incidence and mortality have decreased substantially. Yet it is unknown whether these improvements were consistent across communities of different economic status and geographic regions, for which efforts to improve cardiovascular disease prevention and management may have had variable impact. Objective To determine whether trends in county-level risk-standardized AMI hospitalization and mortality rates varied by county-based median income level. Design Observational study from 1999 to 2013. Setting National study of U.S. counties. Participants County-level risk-standardized (age, sex, race) hospitalization and 1-year mortality rates for AMI from 1999 to 2013 were measured for Medicare beneficiaries ≥65 years. Exposures Counties were stratified by median income percentile using 1999 U.S. Census Bureau data, adjusted for inflation: low (<25th), average (25–75th) or high (>75th) income groups. Main Outcome and Measure We examined the effect of income on the slope of AMI hospitalizations and mortality. We measured differences in rate of change in AMI hospitalizations and mortality by county income and by the 4 U.S. geographic regions. We also tested for a ‘lag’ effect among low-income counties. Results In the 15-year period, AMI risk-standardized hospitalization and mortality rates decreased significantly for all three county income groups. Average hospitalization rates were significantly higher among low-income counties compared with high-income counties, with rates for low-income counties in 2013 lower than for high-income counties in 1999 (853 versus 1,123 per 100,000 person years, respectively). 1-year mortality rates after hospitalization for AMI were similar across county income groups, decreasing from 1999 (31.5%, 31.4%, and 31.1%, for high, average and low income counties, respectively) to 2013 (26.2%, 26.1%, and 25.4%). The rate of decline in AMI hospitalizations was similar for all county income groups; however, low-income counties lagged behind high-income counties by 4.3 (95% CI 3.1 to 5.9) years. There were no differences in trends across geographic regions. Conclusion and Relevance AMI hospitalization and mortality rates declined among counties of all income levels, though hospitalization rates among low-income counties lag behind. These findings lend support for a more targeted community-based approached to AMI prevention.

Association of Neighborhood-Level Marginalization With Health Care Use and Clinical Outcomes Following Hospital Discharge in Patients Who Underwent Coronary Catheterization for Acute Myocardial Infarction in a Single-Payer Health Care System

“…1,2,[5][6][7][8][9][10][11][12]23,24,[33][34][35] US samples have demonstrated poorer survival 36 and even starker SES gradients. [37][38][39][40][41][42] Contrasting these studies, disparities in mortality observed in our cohort were relatively modest. Yet, reasons for worsened outcomes in the highest marginalized patients remain unexplained.…”

“…Canadian data have consistently shown the presence of income-related disparities in mortality and access to care following AMI. 1,2,5–12,23,24,33–35 Similar findings have been demonstrated in the United States 37–42 and in other countries with universal health care. 33,45–47 Our study extends prior findings by including a contemporary cohort of patients with AMI, considering dimensions of marginalization beyond income, and performing a comprehensive evaluation of posthospitalization care and outcomes.…”

Incidence, Risk Factors, and Outcomes Associated With In-Hospital Acute Myocardial Infarction

“…Risk factors associated with an increased risk of in-hospital AMI included a history of atherosclerotic disease and cardiovascular risk factors in addition to markers of physiological stress (eg, elevated heart rate, low hemoglobin, and elevated white blood cell count). While contemporary studies suggest the mortality for AMI that begins outside the hospital is approximately 13% at 30 days and 25% at 1 year, we observed mortality for in-hospital AMI that exceeded 25% at 30 days and approached 60% at 1 year. This study highlights the importance of in-hospital AMI as a common and high-risk clinical condition among hospitalized patients.…”

Marginalized Neighborhoods and Health Outcomes in Younger Myocardial Infarction Survivors

“…Many studies have established associations between socioeconomic status and outcomes after an AMI . Our study extends current knowledge in several ways.…”

“…Many studies have established associations between socioeconomic status and outcomes after an AMI. 4,16,[29][30][31][32][33][34][35][36][37][38][39][40][41] Our study extends current knowledge in several ways. First, while the impacts of individuals' socioeconomic status in cardiovascular outcomes is well established, few studies have examined the role of the neighborhood environment on AMI outcomes.…”