Figure 1.

Median FEV₁ has improved over the past two decades in those with cystic fibrosis (CF) by greater than 10% in 2009 (upper curve) compared with 1989 (lower curve). When first measured in school-age children with CF, median FEV₁ is usually within the normal range (>80% predicted), where it remains throughout childhood (1). This indicates that factors such as treatment during the preschool years must have also improved. Despite this generational improvement in lung function, a large majority of children have underlying bronchiectasis, indicative of irreversible airway damage occurring irrespective of relatively preserved FEV₁.