Clinical characteristics and burden of illness in a cohort of severe asthma patients

Abstract

Objectives: Describe demographic and clinical traits among patients with severe asthma (SA) and a subset of patients with inadequately controlled severe eosinophilic asthma (SEA). Methods: IDEAL study (201722; NCT02293265) is a cross-sectional cohort of SA patients (age ≥12 years, high-dose ICS + additional controller/s for ≥12 months) recruited from specialist clinics in 6 countries. Inadequately controlled SEA was defined as (1) blood eosinophil count of ≥300 cells/μL in the past 12 months prior to study visit OR ≥150 cells/μL at study visit AND (2) ≥2 or more severe exacerbations of asthma (requiring systemic corticosteroid and/or emergency room (ER) visit and/or hospitalization) in the past 12 months. Extensive medical history supplemented with existing medical records and a blood sample were collected. Results: The cohort consisted of 670 SA patients, of whom 137 (20%) had SEA. Compared to the total SA cohort, the subset with SEA had equal proportion of females (62%), was slightly younger (mean: 48 vs. 51 yrs) and had more significant smoking history (45% vs. 36%). Mean of severe exacerbations was 3.2 vs. 1.2/patient-year and 23% vs 9% had ≥1 asthma hospitalization, with more frequent regular OCS use (20% vs. 14%). Further, higher levels of IgE (179 vs. 155 KU/L), lower FEV 1 values (64 vs. 68 FEV 1 % pred.) and more frequent comorbidities were observed. Conclusions: The IDEAL study shows a considerable disease burden in a cohort of patients with severe asthma, with impaired lung function and on average more than one exacerbation/yr. The subset with inadequately controlled severe eosinophilic asthma with more than 3 exacerbations/yr seems to drive much of this disease burden. Funded by GSK.