Year-to-year changes in lung function in individuals with cystic fibrosis

J Cyst Fibros. 2010 Jul;9(4):250-6. doi: 10.1016/j.jcf.2010.04.002. Epub 2010 May 14.


Background: We examined the year-to-year change in FEV(1) for individuals and the overall cystic fibrosis population to better understand how individual trends may differ from population trends.

Methods: We calculated individual yearly changes using the largest annual FEV(1) percent predicted (FEV(1)%) measurement in 20,644 patients (6-45years old) included in the Epidemiologic Study of Cystic Fibrosis. We calculated yearly population changes using age-specific medians.

Results: FEV(1)% predicted decreased 1-3 points per year for individuals, with maximal decreases in 14-15year olds. Population changes agreed with individual changes up to age 15; however after age 30, yearly population change approximated zero while individual FEV(1)% predicted decreases were 1-2 points per year.

Conclusions: Adolescents have the greatest FEV(1)% predicted decreases; however, loss of FEV(1) is a persistent risk in 6-45year old CF patients. Recognizing individual year-to-year changes may improve patient-specific care and may suggest new methods for measuring program quality.

Publication types

  • Multicenter Study

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Child
  • Cystic Fibrosis / physiopathology*
  • Disease Progression
  • Female
  • Forced Expiratory Volume
  • Humans
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Young Adult