Case Study Fractional exhaled Nitric Oxide (FeNO) testing 1 February 2023 Share Share on Linkedin Share on X Share via email Case Study Medicine safety & optimisation Kent and MedwaySurreySussex Health and care professionals FeNO is a non-invasive test to measure the amount of nitric oxide in an exhaled breath, a biomarker for airway inflammation. It contributes to faster, and more effective asthma diagnosis and can monitor patient response to asthma treatments. Between April 2021 and February 2023, 51 devices were spread across Kent, Surrey and Sussex benefitting c. 4,000 patients and preventing 1,450 false positive diagnoses – an equivalent saving of £420,380 a year. Find out more in the impact reporting.