AN ECOLOGIC STUDY OF ACCESS TO ACUTE STROKE CARE, MORTALITY AND ITS CORRELATES IN THE STROKE BELT

Importance: Stroke is leading cause of death in the United States, but quick access to treatment has been shown to result in better outcomes and improved mortality. Among the many barriers to access, geographic proximity to hospitals certified in stroke care may also play a role.Objectives: To calculate county-level measures of accessibility to certified stroke hospitals using GIS, and to examine its relationship with county stroke mortality while controlling for other county-level potential confounders.Methods: Ecologic study using county mortality rates and census data to recreate stroke death counts for use in traditional, and a geographically weighted Poisson regression model for the eleven states of the Stroke Belt (N=1033).Results: Counties farther than 60km from a stroke certified hospital displayed a 2.8% increase in stroke mortality rates while controlling for a county’s percentage of diagnosed diabetics, leisure-time physical inactivity, population aged 65 and over, black or African American population, Medicare Part D beneficiaries non-adherent to their blood pressure medication regiment, county smoking prevalence, annual PM2.5 concentrations, distressed community index score, and state’s decision to expand Medicaid. Some covariates displayed relationships with mortality that were non-stationary and varied over the study area.Conclusions: Thoughtful consideration should be made in studies of geographic access to the methods used for estimation, along with the possibility of a non-linear and nonstationary relationship with study outcomes.