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Understanding the relationship between environmental quality and asthma using claims data
Citation:
Gray, C., A. Rzhetsky, K. Rappazzo, Y. Jian, S. Grabich, J. Jagai, L. Messer, AND D. Lobdell. Understanding the relationship between environmental quality and asthma using claims data. International Society for Environmental Epidemiology Annual Meeting, Rome, ITALY, September 01 - 04, 2016.
Impact/Purpose:
To examine the associations between asthma claims data and the EQI.
Description:
In 2014, approximately 17.7 million (7.4%) of United States (U.S.) adults had asthma. In 2009 alone, asthma caused 479,300 hospitalizations and 1.9 million emergency room visits. Asthma has been associated with exposure to air pollution and socioeconomic status, and reductions in atopic sensitization, an asthma precursor, have been associated with green space exposure, suggesting a role of environmental quality. We linked the Environmental Quality Index (EQI), representing 5 environmental domains (air, water, land, built, and sociodemographic) for all US counties (N=3,141) from 2000—2005 to Truven Health’s MarketScan individual claims database to examine associations between county-level EQI and asthma among U.S. adults ages 18-65 from 2003-2010. We defined asthma as having at least 1 claim (International Classification of Disease 9th edition, code 493) during the study period. We used random intercept multi-level Poisson regression clustered by county, adjusted for 10-year age category and sex, to estimate fixed effects of quintiles of the EQI on asthma prevalence. We examined modification by urbanicity through stratification by 4 rural-urban continuum codes (RUCC) ranging from most urban (RUCC1) to rural (RUCC4). Approximately 3% of adults in MarketScan have asthma claims. Comparing the highest EQI quintile (worst quality) to lowest EQI quintile (best quality), we observed increased asthma claims associated with worse environmental quality (prevalence ratio (PR)=1.19; 95% confidence interval (CI): 1.12, 1.26). Associations varied by rural-urban status; asthma prevalence was most positively associated with environmental quality in most urban areas (RUCC 1: PR= 1.14 (1.06, 1.22), RUCC 2: PR= 1.02(0.86, 1.19), RUCC 3: PR=0.97 (0.89, 1.07)). Environmental quality is associated with asthma, and effects are modified by rural-urban status. This abstract does not necessarily reflect EPA policy.