Table 2—

Annual change of forced expiratory volume in one second (FEV₁) and forced vital capacity (FVC) in 52 cystic fibrosis patients

	FEV₁	FVC
% pred Z	−2.0±3.8	−0.8±3.1
% pred K	2.2±6.2	−0.8±3.2
% pred Q	−2.1±3.4	−1.0±2.8
% pred W	−2.2±3.6	−0.7±3.1

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