Background: The fraction of exhaled nitric oxide (FENO) is a useful marker of asthma control. The FENO measurement with two hand-helded analyzers (NObreath® and NIOX Vero®) may be more affordable, no studies have examined the differences in FENO values measured with those methods in adult.
Methods: The study population comprised 44 subjects at our outpatient clinic. FeNO values (FENOb and FENOv) were measured by two methods (NObreath® and NIOX Vero®).
Results: FENOb values were significantly correlated with FENOv (r = 0.911, p < 0.001). However, FENOv values were high compared with FENOb (FENOv = 1.40 × FENOb).
Conclusion: Differences exist in the values of FENO measured by two hand-helded analyzers: conversion equations are needed to compare the FENO values between these methods.
Keywords: NIOX Vero; NObreath; the fraction of exhaled nitric oxide.