The study is useful for diagnosis and monitoring of asthma regardless of whether an individual is in asthma or not. If FeNO levels are above 50 ppb in adults or above 35 ppb in children, this indicates that inflammatory airways are likely to develop and that an individual is likely to respond well to corticosteroids. Changes in the FeNO levels of an individual after starting treatment also indicate that treatment is successful.

The device was purchased with a grant from the Heart Foundation. Akureyri hospital thanks for their support.