An increase of <50% in fractional exhaled nitric oxide (FeNO) during a 3-month period is unlikely to be clinically meaningful in children with asthma, according to the results of a study published in Pediatric Pulmonology.
Researchers used clinical data from 7 clinical trials that included FeNO measurements obtained from children with asthma. Both absolute and percentage change FeNO measurements during stable and unstable 3-month periods were examined to determine what percentage increase was likely to be clinically meaningful. Stable periods were defined as 2 successive assessments during the course of 3 months with controlled asthma, where the dose of inhaled corticosteroids remained unchanged and there was no exacerbation requiring oral corticosteroid treatment.
A total of 1112 participants were analyzed, 665 of whom had ≥1 stable period. For all stable participants combined, the mean percentage change was +26%. In addition, there were 48 individuals identified who experienced consecutive periods of stable asthma followed by unstable asthma. There were no differences in change in FeNO between the stable and unstable periods.
The researchers noted that these results may be relevant to clinicians when interpreting repeated FeNO measurements, particularly when making treatment decisions for a child already diagnosed with asthma.
Fielding S, Pijnenburg M, de Jongste J, et al. What is a clinically meaningful change in exhaled nitric oxide for children with asthma? [published January 7, 2020]. Pediatr Pulmonol. doi:10.1002/ppul.24630