A recent study published in the Annals of Allergy, Asthma & Immunology reveals significant variability in the prevalence of severe persistent asthma among patients with asthma across different states in the United States. The study, led by Carlos A. Camargo Jr., MD, DrPH, from Massachusetts General Hospital, highlights disparities in exacerbations, emergency department (ED) visits, hospitalizations, and medication use.
The prevalence of severe persistent asthma ranged from 19.6% in New Mexico to 31.9% in Alaska, indicating a substantial difference in disease burden. The study aimed to explore regional disparities and identify unmet medical needs among asthma patients in the U.S.
Asthma, affecting approximately 25 million people in the United States, is a complex respiratory disease with varying prevalence and severity at the national and regional levels. The researchers used real-world data to map the burden of asthma, considering factors such as prevalence, severity, exacerbations, asthma control status, and medication use.
The Southern United States had the highest proportion of asthma patients with severe persistent asthma, with the prevalence reaching 37.4%. The states with the highest percentages of uncontrolled asthma included Arizona, Louisiana, Hawaii, Texas, and Michigan.
The researchers utilized data from the IQVIA open-source longitudinal prescription and medical claims database and the IQVIA PharMetrics Plus closed-claims database. The cohort included 2,092,799 patients with asthma aged 12 years and older, with 23.7% having severe persistent asthma.
The study revealed considerable geographic heterogeneity across U.S. states. Severe persistent asthma was most prevalent in Alaska, Nebraska, and South Dakota, while least prevalent in Florida, Delaware, and New Mexico.
Medication use patterns showed variations, with systemic corticosteroids used by 60.8% of patients with severe persistent asthma. The use of corticosteroids varied across states, with the highest rates in Mississippi, Louisiana, and Alabama and the lowest rates in Vermont, Oregon, and Alaska.
Exacerbation rates also demonstrated regional differences, with Louisiana, Oklahoma, and Texas having the highest rates, while Idaho, Alaska, and Vermont had the lowest. Emergency department visits or hospitalizations occurred in 13.4% of patients, with Nevada, Wisconsin, and the District of Columbia reporting the highest rates and Vermont, Tennessee, and North Carolina reporting the lowest.
Over half of the patients were classified as having uncontrolled or sub-optimally controlled severe persistent asthma, with rates of severe uncontrolled asthma varying between states. Rates of biologic therapy use among patients with severe uncontrolled asthma ranged from 27.9% in Mississippi to 2.2% in Hawaii.
The study provides valuable insights into the geographic diversity of disease control and unmet medical needs among U.S. patients with severe asthma. While the reasons for these differences may include genetic, environmental, and social factors, further research is needed to explore the causes behind state-level variations in severe persistent asthma. The study’s descriptive nature calls for additional investigations to understand the factors contributing to these disparities fully. Meanwhile, an interactive tool is available for healthcare providers to explore the impact of asthma in their respective states.
