Abstract Rationale Understanding the clinical and biological characteristics of asthma patients at higher risk of exacerbation identified by elevated fractional exhaled nitric oxide (FeNO) (≥25 ppb) and blood eosinophils (EOS) (150-300 cells/μL) is essential to optimize disease management and identify populations likely to benefit from targeted therapies. This analysis aims to describe the characteristics of these patients compared with the general asthma population. Methods A descriptive, retrospective analysis was conducted using real-world data from Optum’s de-identified Market Clarity Data (Optum® Market Clarity) (Q4 2015-Q1 2024). Three cohorts were analyzed: elevated FeNO (≥25 ppb), elevated EOS (150-300 cells/μL), and overall asthma population, and these cutoffs were chosen based on current literature identifying patients at risk for exacerbations as well as data available from the database. Comparisons with overall asthma group were performed in two separate analyses (FeNO vs overall and EOS vs overall). Comparisons were made using demographic data, comorbidities, clinical characteristics, medication utilization, and provider prescribing behaviors. Results 9.51 million patients with asthma were included, with 327,000 having elevated FeNO and 171,120 patients having elevated EOS. Patients with elevated FeNO or EOS were more likely to be elderly (65 years: 25.7% FeNO, 26.8% EOS, 14.9% overall asthma population), non-Hispanic (74.3%, 70.5%, 64.5%), with higher representation in the Middle Atlantic region (20.8%, 24.9%, 13.8%), higher rates of sedentary lifestyle (14.4%, 14.9%, 5.0%) and overweight (24.8%, 25.3%, 14.9%). There was higher prevalence of allergic rhinitis, chronic allergic contact dermatitis, and chronic rhinosinusitis with nasal polyps in the elevated FeNO and EOS groups than in the overall asthma population. Patients with elevated FeNO or EOS had a higher comorbidity burden (mean conditions per patient of 6.2 and 7.0 compared with 5.0 in overall asthma population) and Charlson Comorbidity Index (CCI) score ≥3 was 24.2%, 40.9%, and 23.7%, respectively. Treatment patterns revealed increased use of systemic corticosteroids (SCS) in both groups, including higher use of oral corticosteroids with oral prednisolone prescribed in 23.5%, 10.8%, and 6.6% across FeNO, EOS, and overall asthma populations. In emergency medicine, SCS was prescribed in 27%, 13.8%, and 12.5% patients. These groups had more frequent average per-patient office visits (2.0, 1.8, 1.0) and emergency room visits (0.4, 0.5, 0.3). Conclusion High-exacerbation risk asthma patients, identified by elevated EOS and FeNO levels, exhibit distinct demographic, clinical, and treatment characteristics compared with the general asthma population. These key differences may help identify these patients earlier in their disease course. This abstract is funded by: Sanofi
Nazarey et al. (2026) studied this question.