Objectives: Fractional exhaled nitric oxide (FeNO) is a marker for type 2 airway inflammation. The objective of this study was to evaluate the cost-effectiveness and budget impact of FeNO monitoring for management of adult asthma in Spain.
Methods: A cost-effectiveness analysis model was used to evaluate the effect on costs of adding FeNO monitoring to asthma management. Over a 1-year period, the model estimated the incremental cost per quality-adjusted life year and incremental number of exacerbations avoided when FeNO monitoring was added to standard guideline-driven asthma care compared with standard care alone. Univariate and multivariate sensitivity analyses were applied to explore uncertainty in the model. A budget impact model was used to examine the impact of FeNO monitoring on primary care costs across the Spanish health system.
Results: The results showed that adding FeNO to standard asthma care saved €62.53 per patient-year in the adult population and improved quality-adjusted life years by 0.026 per patient-year. The budget impact analysis revealed a potential net yearly saving of €129 million if FeNO monitoring had been used in primary care settings in Spain.
Conclusions: The present economic model shows that adding FeNO to the treatment algorithm can considerably reduce costs and improve quality of life when used to manage asthma in combination with current treatment guidelines.

Key words: Asthma management, Biomarker, Budget impact, Cost-effectiveness, FeNO, Guidelines, Exhaled nitric oxide