Change of forced expiratory volume in one second (FEV_{1}) and forced vital capacity (FVC) during the study in a subgroup of 35 children aged ≥11 yrs

Data are presented as mean±sd unless otherwise stated

Z: using reference equation described in Zapletal et al. 9

K: using reference equation described in Knudson et al. 8

Q: using reference equation described in Quanjer et al. 4

W: using reference equation described in Wang et al. 6