Year-to-year changes in lung function in individuals with cystic fibrosis.
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.
Liou
Theodore G
TG
University of Utah, 26 North 1900 East, Salt Lake City, UT 84132-4701,USA. ted.liou@utah.edu
Elkin
Eric P
EP
Pasta
David J
DJ
Jacobs
Joan R
JR
Konstan
Michael W
MW
Morgan
Wayne J
WJ
Wagener
Jeffrey S
JS
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D003550:Cystic Fibrosis / Q000503:physiopathology*; D018450:Disease Progression; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D055815:Young Adult
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