Urban residence, neighborhood poverty, race/ethnicity, and asthma morbidity among children on Medicaid

Background: Although poor-urban (inner-city) areas are thought to have high asthma prevalence and morbidity, we recently found that inner cities do not have higher prevalent pediatric asthma. Whether asthma morbidity is higher in inner-city areas across the United States is not known. Objective: This study sought to examine relationships between residence in poor and urban areas, race/ethnicity, and asthma morbidity among children with asthma who are enrolled in Medicaid. Methods: Children aged 5 to 19 enrolled in Medicaid in 2009 to 2010 were included. Asthma was defined by at least 1 outpatient or emergency department (ED) visit with a primary diagnosis code of asthma over the 2-year period. Urbanization status was defined at the county level and neighborhood poverty at the zip-code level. Among children with asthma, logistic models were created to examine the effects of urbanization, neighborhood poverty, and race/ethnicity on rates of asthma outpatient visits, ED visits, and hospitalizations. Results: This study included 16,860,716 children (1,534,820 with asthma). Among children enrolled in Medicaid, residence in inner-city areas did not confer increased risk of prevalent asthma in either crude or adjusted analyses, but it was associated with significantly more asthma-related ED visits and hospitalizations among those with asthma in crude analyses (risk ratio, 1.48; 95% CI, 1.24-1.36; and 1.97; 95% CI, 1.50-1.72, respectively) and when adjusted for race/ethnicity, age, and sex (adjusted risk ratio, 1.23; 95% CI, 1.08-1.15; and 1.62; 95% CI, 1.26-1.43). Residence in urban or poor areas and non-Hispanic black race/ethnicity were all independently associated with increased risk of asthma-related ED visits and hospitalizations. Conclusions: Residence in poor and urban areas is an important risk factor for asthma morbidity, but not for prevalence, among low-income US children.