Measurement of fractional exhaled nitric oxide in real-world clinical practice alters asthma treatment decisions.

Background: Assessment of asthma using clinical measures alone often fails to detect underlying airway inflammation. Fractional exhaled nitric oxide (FeNO) is a recognized biomarker of type 2 airway inflammation in asthma. Measurement of FeNO is instrumental in the assessment and management of patients with corticosteroid-sensitive asthma. Objective: To determine the impact of measuring FeNO on asthma management in real-world clinical practices. Methods: Clinicians from 337 US practices performed a clinical assessment and recorded treatment plans before and after measuring FeNO in 7,901 patients with asthma. Airway inflammation was classified as low, intermediate, or high according to the clinician's usual procedures, including clinical examination, spirometry, and symptoms. Clinicians recorded asthma medication plans, indicating medications to be initiated, continued, or stopped. FeNO measurement was performed, followed by documentation of any change(s) in the treatment plans based on the FeNO value (eg, initiating new medications or changing the dose of or discontinuing existing medications). Results: Clinical assessment was concordant with FeNO measurement in only 56% of cases, matching FeNO more frequently in patients with low inflammation (64%) vs high inflammation (34%). After FeNO measurement, clinicians modified their treatment plan in 31% and altered prescriptions for inhaled corticosteroids in 90% of cases. Inhaled corticosteroids were initiated or their dose increased in 66% of patients with high inflammation but discontinued or their dose decreased in only 9% of patients with low inflammation. Conclusion: Measurement of FeNO enabled clinicians to assess underlying airway inflammation, leading to a significant revision of their treatment plans compared with real-world clinical assessment of asthma alone. (C) 2018 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc.