Abstract
BACKGROUND: The extent to which asthma-related ED visit incidence rates vary from neighborhood to neighborhood and predictors of neighorbood-level asthma ED visit burden are not well understood. OBJECTIVE: To describe the census tract-level spatial distribution of asthma-related emergency department visits in Central Texas and identify neighborhood-level characteristics that explain variability in neighborhood-level asthma ED visit rates. METHODS: Conditional autoregressive models were used to examine the spatial distribution of asthma-related ED visit incidence rates across Travis County, TX census tracts and to assess the contribution of census tract characteristics to their distribution. RESULTS: There were distinct patterns in ED visit incidence rates at the census tract scale, which 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. CONCLUSIONS: Variability in asthma ED visit incidence rates are apparent at a smaller spatial scales than previously examined. The majority of the variability in census tract-level asthma ED visit rates in Central Texas is not explained by racial and ethnic composition or other neighborhood features. Race/ethnicity-specific estimates of neighborhood ED visit rates may be useful for identifying high burden neighborhoods for specific ethnic/racial groups, which otherwise would go unrecognized.