TABLE 2

Differences in respiratory function and exacerbations between patients with cystic fibrosis who had at least one sputum culture positive for Achromobacter xylosoxidans (Ax+) and cystic fibrosis patients uninfected by A. xylosoxidans (Ax−)

CharacteristicsControl subjects (n=36)Patients (n=36)p-value
Lung function
 ΔFEV1 %·year−1−3.05±0.54−5.27±0.470.002#
 ΔFEV1 mL·year−1−63.8±18.5−153.6±16.1<0.001#
 ΔFVC %·year−1−2.42±0.86−3.58±0.560.18
 ΔFVC mL·year−1−101.0±32.1−160.0±21.00.06
Exacerbations n
 Year before baseline1.5 (0.0–5.0)2.0 (1.0–3.5)0.77
 Year after baseline0.5 (0.0–4.0)2.0 (1.0–4.0)0.16
 Years 1 and 2 after baseline+5.0 (4.0–6.0)6.0 (4.0–8.0)0.034
 Years 1–3 after baseline +7.0 (5.0–10.0)9.0 (7.0–12.0)0.033

Data are presented as β±se (slope of change calculated from the baseline (time of bacterial detection)) or median (interquartile range), unless otherwise stated. FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity. #: Calculated from the group×time interaction term of the linear mixed model;: calculated using a generalised linear mixed model (Poisson regression model) including matched sets as a random effect; +: cumulative number of exacerbations.