Unadjusted coefficient | 95% CI | p-value | Adjusted coefficient^{#} | 95% CI | p-value | |

Intercept | 69.09 | 66.78–71.39 | <0.001 | 70.97 | 68.52–73.42 | <0.001 |

Time | −1.35 | −1.54 – −1.15 | <0.001* | −1.36 | −1.55 – −1.17 | <0.001* |

CFTR modulator | 1.51 | 0.49–2.48 | 0.002* | 1.51 | 0.56–2.46 | 0.002* |

Time : CFTR modulator | 0.86 | 0.31–1.41 | 0.002* | 0.88 | 0.35–1.39 | 0.001* |

Interpretation: the intercept represents the mean FEV_{1} % pred of the study population at the time of CFTR modulator initiation (baseline). The coefficient of time (in years) reflects the mean annual FEV_{1} % pred decline in the years before CFTR modulator initiation. The coefficient CFTR modulator indicates the acute change in mean FEV_{1} % pred after CFTR modulator initiation, whereas time : CFTR modulator represents the change in annual FEV_{1} % 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.