When asymptomatic asthmatic children in clinical remission stopped taking steroids, a NIOX Value of more than 49 ppb, 2 to 4 weeks later was an effective predictor of asthma relapse (Pijnenburg 2005) .
Pijnenburg MW, Hofhuis W, Hop WC, De Jongste JC. Exhaled nitric oxide predicts asthma relapse in children with clinical asthma remision. Thorax 2005;60:215-8.