A Review of the Utility and Cost Effectiveness of Monitoring Fractional Exhaled Nitric Oxide (FeNO) in Asthma Management.

It results in substantially higher direct and indirect costs as well as an increased mortality risk and poorer quality of life, particularly among patients with difficult-to-control asthma. While several physiologic tests, including spirometry, are typically used to diagnose and characterize asthma, they do not provide the sensitivity and specificity required to accurately reflect the underlying heterogeneous inflammatory pathways. Fractional exhaled nitric oxide (FeNO) is a validated, noninvasive biomarker for T2-driven (i.e., allergic) airway inflammation that correlates with sputum eosinophils at or greater than 3% across various asthma phenotypes. Its use as a biomarker in asthma is well supported by numerous peer-reviewed articles and guidelines. There is also evidence that its use in clinical settings for patients with uncontrolled asthma is cost effective, given its ability to improve the accurate diagnosis of asthma, monitor treatment response, optimize inhaled corticosteroid dosing, and identify patient nonadherence. It may also have a role in identifying patients who are possible candidates for treatment with biologics.