These data suggest that lung clearance index may be a useful surveillance tool to monitor structural lung disease in preschool and school-age children with CF. However, lung clearance index cannot replace chest computed tomography to screen for bronchiectasis in this population.

The onset of lung disease in infancy, specifically the occurrence of lower respiratory tract infection, is associated with low lung function in young children with cystic fibrosis. Deficits in lung function measured in infancy persist into childhood, emphasizing the need for targeted therapeutic interventions in infancy to maximize functional outcomes later in life.

Despite substantial increases in the use of less invasive ventilation after birth, there was no significant decline in oxygen dependence at 36 weeks and no significant improvement in lung function in childhood over time. (Funded by the National Health and Medical Research Council of Australia and the Victorian Government's Operational Infrastructure Support Program.).