Geographic disparities in the incidence and outcomes of hospitalized myocardial infarction: does a rising tide lift all boats?

Background: Improvements in prevention have led to declines in incidence and mortality of myocardial infarction (MI) in selected populations. However, no studies have examined regional differences in recent trends in MI incidence, and few have examined whether known regional disparities in MI care have narrowed over time.

Methods And Results: We compared trends in incidence rates of MI, associated procedures and mortality for all US Census Divisions (regions) in Medicare fee-for-service patients between 2000-2008 (292 773 151 patient-years). Two-stage hierarchical models were used to account for patient characteristics and state-level random effects. To assess trends in geographic disparities, we calculated changes in between-state variance for outcomes over time. Although the incidence of MI declined in all regions (P<0.001 for trend for each) between 2000-2008, adjusted rates of decline varied by region (annual declines ranging from 2.9-6.1%). Widening geographic disparities, as measured by percent change of between-state variance from 2000-2008, were observed for MI incidence (37.6% increase, P=0.03) and percutaneous coronary intervention rates (31.4% increase, P=0.06). Significant declines in risk-adjusted 30-day mortality were observed in all regions, with the fastest declines observed in states with higher baseline mortality rates.

Conclusions: In a large contemporary analysis of geographic trends in MI epidemiology, the incidence of MI and associated mortality declined significantly in all US Census Divisions between 2000-2008. Although geographic disparities in MI incidence may have increased, regional differences in MI-associated mortality have narrowed.