Neighborhood-level variability in asthma-related emergency department visits in Central Texas

Abstract

The extent to which asthma-related emergency department (ED) visit incidence rates vary from neighborhood to neighborhood and the predictors of neighorbood-level asthma ED visit burden are not well understood. Our aim was to describe the census tract-level spatial distribution of asthma-related ED visits in Central Texas and identify neighborhood-level characteristics that explain variability in neighborhood-level asthma ED visit rates. Conditional autoregressive models were used to examine the spatial distribution of asthma-related ED visit incidence rates across Travis County, Texas, census tracts and to assess the contribution of census tract characteristics to their distribution. There were distinct patterns in ED visit incidence rates at the census tract scale that were largely unexplained by socioeconomic or selected built environment neighborhood characteristics. Racial and ethnic composition explained 33% of the variability of ED visit incidence rates across census tracts. Spatial patterns and the census tract predictors of ED visit incidence rates differed by racial and ethnic groups. Variability in asthma ED visit incidence rates areapparent at smaller spatial scales than previously examined.Most of the variability in census tract-level asthma ED visitrates in Central Texas is not explained by racial andethniccomposition or other neighborhood features. Race/ethnicity-specific estimates of neighborhood ED visit rates may be useful for identifying high-burden neighborhoods for specific ethnic and racial groups that otherwise would go unrecognized.