Using fractional exhaled nitric oxide to guide step-down treatment decisions in asthma: practical considerations.

Wang K, Verbakel JY, Oke J, Fleming-Nouri A, Harada N, Atsuta R, Fujisawa T, Kawayama T, Inoue H, Lazarus S, Szefler S, Martinez FD, Shaw D, Pavord ID, Thomas M