Road traffic density and recurrent asthma emergency department visits among Medicaid enrollees in New York State 2005-2015

Abstract Background Environmental exposures such as traffic may contribute to asthma morbidity including recurrent emergency department (ED) visits. However, these associations are often confounded by socioeconomic status and health care access. Objective This study aims to assess the association between traffic density and recurrence of asthma ED visits in the New York State (NYS) Medicaid population between 2005 and 2015. Methods The primary outcome of interest was a recurrent asthma ED visit within 1-year of index visit. Traffic densities (weighted for truck traffic) were spatially linked based on home addresses. Bivariate and multivariate logistic regression analyses were conducted to identify factors predicting recurrent asthma ED visits. Results In a multivariate model, Medicaid recipients living within 300-meters of a high traffic density area were at a statistically significant risk of a recurrent asthma ED visit compared to those in a low traffic density area (OR=1.31; 95% CI:1.24 – 1.38). Additionally, being male (OR=1.24; 95% CI:1.20 – 1.27), being on cash assistance (OR=1.27; 95% CI:1.24 – 1.31) and receiving supplemental security income (OR=1.23; 95% CI:1.18 – 1.27) was associated with a higher risk of recurrent asthma ED visit. Black non-Hispanics (OR=1.20; 95% CI:1.10 – 1.31), Hispanics (OR=1.52; 95% CI:1.46 – 1.59) and those with race listed as “Other” (OR=1.58; 95% CI:1.48 – 1.68) had higher risk of recurrent asthma ED visits as compared to White non-Hispanics. Conclusion We observed significant persistent disparities in asthma morbidity related to traffic exposure and race/ethnicity in a low-income population. Our findings suggest that even within a primarily low-income study population, socioeconomic differences persist. These differences in susceptibility in the extremely low-income group may not be apparent in health studies that use being on Medicaid as a proxy for low income