Association Between Area Socioeconomic Status and Asthma Hospital Admissions

Abstract

P-397 Introduction: Asthma has been estimated to affect 17 million people or over 5% of the total population, with 1.9 million emergency room visits, and 466,000 hospital admissions annually in the US. Because asthma is most common among low socioeconomic status inner-city ethnic minority population groups, an important question is to evaluate and define the extent to which racial and ethnic differences are due to social deprivation status. Understanding the disproportionate increase of asthma in inner cities may provide insight into the roots of the asthma epidemics and more effective disease management. Methods: The data on asthma hospitalizations (ICD-9-CM 493.0–493.9) in Hillsborough County, FL, was collected for the period of 1997–1999. Due to existing etiological and pathological differences, only adult (16 years and above) hospital admissions were selected for further analysis. Calculated standardized asthma hospitalization rates by zip code area of residence were adjusted for age, race and gender differences. Principal component analysis techniques were used reduce the number of significant area socioeconomic status indicators, and to develop a complex area socioeconomic deprivation index. GIS advanced spatial analysis and modeling techniques were used to provide a more accurate average surrogate estimate of environmental exposure to ambient particles, sulfur dioxide and ozone. Stepwise backward selection log-linear regression procedures were used to obtain the best fit final models for asthma hospitalizations in 1997, 1998, and 1999. The accuracy of final socioeconomic deprivation index model was validated by using independent data outside of our study area. Results: The study results revealed that ambient air pollution was not a significant predictor after controlling for area socioeconomic status. Poverty, professional occupation, no vehicle available, overcrowded housing, single parent families, and houses using fuel were found to be significant small-area socioeconomic status predictors of asthma hospitalizations for the period of study. Discussion and Conclusions: The study results support previous findings that severe exacerbation are clustering more frequently within specific geographical areas of residence and could be explained by area demographic, socioeconomic, environmental, and behavioral characteristics. The census-based socioeconomic deprivation index could serve as a powerful tool for describing and monitoring social inequalities in a given community over time. The small-area deprivation index could be applied to identify high risk geographical areas and population groups to develop more effective preventive strategies for asthma management and prevention.