Mapping geographic variability of severe uncontrolled asthma in the United States: Management implications.

BACKGROUND

The US population-level data on asthma morbidity and mortality are available primarily through state-level surveys. We hypothesize that considerable county-level heterogeneity may be obscured by state-level data, thus impeding focused initiatives to improve asthma outcomes.

OBJECTIVE

To assess heterogeneity in the prevalence of uncontrolled, severe, and severe uncontrolled asthma by evaluating state- and county-level morbidity reflected in large administrative claims data sets and identify relationships between pharmacotherapy-based morbidity and the Centers for Disease Control and Prevention's asthma mortality data.

METHODS

Asthma prevalence and morbidity were identified using medical and pharmacy claims from the IQVIA Longitudinal Access and Adjudication Data database (July 2015-June 2018). Heat maps ranked the prevalence of severe uncontrolled asthma by deciles in all 50 states and the District of Columbia, plus 2935 counties. Mortality in states (2016) and 3147 counties (1999-2018) was similarly mapped and ranked and contrasted with claims-based morbidity.

RESULTS

Among 4,506,527 individuals with asthma, 640,936 (14.2%) received age-specific therapy for severe asthma. Of those with severe asthma, 144,232 (22.5%) filled 2 or more annual courses of systemic steroids and were designated as having severe uncontrolled asthma. Most states with high mortality had relatively few patients with severe uncontrolled asthma. A marked correlation between mortality and morbidity and trends by urban vs rural and metropolitan status were found at the county level.

CONCLUSION

Intrastate heterogeneity in the morbidity and mortality of severe uncontrolled asthma at the county level is not evident in state-level analyses. Increased local awareness of systemic corticosteroid use as an indicator of uncontrolled asthma should prompt regional educational and public health efforts to improve outcomes.