Geographic and Racial Variation in Asthma Prevalence and Emergency Department Use among Medicaid-Enrolled Children

Background:  Despite well-disseminated evidence based prevention and practice guidelines, asthma prevalence, treatment and outcomes vary widely at individual and community levels. Asthma disproportionately affects low-income and minority children and related hospitalizations in childhood have substantial costs for Medicaid.

Methods:  2007 Medicaid claims data from 14 southern states was mapped for 550 counties to describe the local area variation in one-year asthma prevalence rates, emergency department (ED) visit rates and racial disparity rate-ratios.

Results:  One-year period prevalence of asthma ranged from 2.8% in Florida to 6.4% in Alabama, with a median prevalence rate of 4.1%. At the county level, prevalence was higher for Black children and ranged from 1.0 % in Manatee County, FL to 21.0% in Hockley County, TX. Rate ratios of prevalence ranged from 0.49 in LeFlore County, MS to 3.87 in Flagler County, FL.

Adjusted asthma ED visit rates ranged from 2.2 per 1000 children in Maryland to 16.5 in Alabama, with a median Black-White ED-visit rate-ratio of 2.4.  Rates were higher for Black children, ranging from 0.80 per 1000 in Wicomico County, MD to 70 per 1000 in DeSoto County, FL. Rate ratios of ED visits ranged from 0.25 in Vernon Parish, LA to 25.28 in Nelson County, KY.

Conclusions and Relevance:  Low-income children with Medicaid coverage still experience substantial variation in asthma prevalence and outcomes from one community to another.  The pattern of worse outcomes for Black children also varies widely across counties. Eliminating this variation could substantially improve overall outcomes and eliminate asthma disparities.