Clinical characteristics and disease control of US asthma patients treated in specialty clinics

Background: GINA 2019 recommends specialist referral for phenotypic assessment and consideration of add-on therapy when Step 4/5 asthma patients persist with symptoms or exacerbations. Aim: To examine clinical characteristics and asthma control as measured by Asthma Control Test (ACT™) and Asthma Impairment and Risk Questionnaire (AIRQ™) in US patients treated in asthma specialty clinics. Methods: 1113 specialty clinic patients of all severity levels aged ≥12 yrs were enrolled in a validation study of AIRQ™. AIRQ™ is a 10-item, equally-weighted, yes/no tool assessing symptom impairment and risk of exacerbations with score ranges indicating well-, not-well, or very poorly controlled disease. Patients with non-asthma chronic lower respiratory conditions or ≥3 months of continuous oral corticosteroids (≥10 mg/day) were excluded. Results: Mean(SD) age 44(11) yrs, 15% 12-17 yrs; 30% male; 78% white; not well- or very poorly controlled: 53% per ACT™, 65% per AIRQ™. Using a 2-week recall, 41% of patients had daytime symptoms on >4 days and 34% awoke from sleep >1 time, 24% reported daily rescue therapy use, and 30% noted limitations in social activities and 54% in ability to exercise. 41% had ≥1 prior-year, chart-confirmed, severe exacerbation. Of patients not well- or very poorly controlled per AIRQTM, 58% had serum eosinophils ≥150/µl and 29% had ≥300/µl. Conclusion: Despite specialty care, many patients had exacerbations and symptoms impacting daily life for which intensification of asthma therapy would be recommended by GINA 2019. Identification of uncontrolled asthma using a questionnaire assessing impairment and risk (AIRQ™) offers a comprehensive option to identify uncontrolled asthma.