Bayesian linear mixed effects model estimates of per cent predicted forced expiratory volume in 1 s (FEV1 % pred) (n=401, years of observation=3844)

Unadjusted coefficient95% CIp-valueAdjusted coefficient#95% CIp-value
Time−1.35−1.54 – −1.15<0.001*−1.36−1.55 – −1.17<0.001*
CFTR modulator1.510.49–2.480.002*1.510.56–2.460.002*
Time : CFTR modulator0.860.31–1.410.002*0.880.35–1.390.001*

Interpretation: the intercept represents the mean FEV1 % pred of the study population at the time of CFTR modulator initiation (baseline). The coefficient of time (in years) reflects the mean annual FEV1 % pred decline in the years before CFTR modulator initiation. The coefficient CFTR modulator indicates the acute change in mean FEV1 % pred after CFTR modulator initiation, whereas time : CFTR modulator represents the change in annual FEV1 % pred decline in the years after CFTR modulator initiation compared to the years before. CFTR: cystic fibrosis transmembrane conductance regulator. #: coefficients were adjusted for the main effects of sex, age at baseline and the interaction effect of age at baseline with time; *: significance level p<0.05.