Low socioeconomic status is associated with worse lung function in the Danish cystic fibrosis population

Extract

To the Editor:

Low socioeconomic status is associated with worse lung function and greater risk of death in people with cystic fibrosis (CF) in the UK and USA, but there are no population level studies from other countries. A feature of previous analyses of inequalities in lung function in CF by socioeconomic status has been the identification of a lung function deficit in more disadvantaged children, which is evident as soon as spirometry can be routinely undertaken at ∼5–6 years of age. The finding of a fixed lung function deficit in the most deprived children in the early years of life has important policy implications, and suggests that deprivation has a detrimental effect on lung health in the early years of a child’s life.

We questioned whether similar patterns were evident in other CF populations, so assessed the effect of socioeconomic status on lung function trajectory measured by forced expiratory volume in 1 s (FEV₁) % predicted in the Danish population. Therefore, we undertook a retrospective, longitudinal, cohort study of all children and adults with CF who had contributed lung function measures to the Danish CF registry between 1969 and 2010 who could be linked to the national level administrative registers.