title: Risk factors for rate of decline in forced expiratory volume in one second in children and adolescents with cystic fibrosis.
abstract: OBJECTIVE
  To characterize the rate of decline of forced expiratory volume in 1 second (FEV(1)) in children and adolescents with cystic fibrosis and to identify and compare risk factors associated with FEV(1) decline.
  
  
  METHODS
  The rate of decline in FEV(1)% predicted over 3 to 6 years in 3 different age groups was determined. Risk factors for decline were identified and compared among and within age groups as a function of disease severity with repeated-measures, mixed-model regression.
  
  
  RESULTS
  Mean (+/-SD) baseline FEV(1)% predicted was 88.4% +/- 20.5% for 6- to 8-year-olds (n = 1811), 85.3% +/- 20.8% for 9- to 12-year-olds (n = 1696), and 78.4% +/- 22.0% for 13- to 17-year-olds (n = 1359). Decline in FEV(1)% predicted/year was -1.12, -2.39, and -2.34, respectively. High baseline FEV(1) and persistent crackles were significant independent risk factors for decline across all age groups. Female sex, Pseudomonas aeruginosa infection, low weight-for-age, sputum, wheezing, sinusitis, pulmonary exacerbations treated with intravenous antibiotics, elevated liver test results, and pancreatic insufficiency were also identified as independent risk factors in some age groups.
  
  
  CONCLUSIONS
  This study identifies risk factors for FEV(1) decline in children and adolescents with cystic fibrosis. Clinicians should not be reassured by high lung function, particularly in young children, because this factor, among others, is independently associated with steeper decline in FEV(1).
authors.affiliation: Department of Pediatrics, Rainbow Babies and Children's Hospital and Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA. michael.konstan@case.edu
authors.forename: Michael W
authors.initials: MW
authors.lastname: Konstan
authors.forename: Wayne J
authors.initials: WJ
authors.lastname: Morgan
authors.forename: Steven M
authors.initials: SM
authors.lastname: Butler
authors.forename: David J
authors.initials: DJ
authors.lastname: Pasta
authors.forename: Marcia L
authors.initials: ML
authors.lastname: Craib
authors.forename: Stefanie J
authors.initials: SJ
authors.lastname: Silva
authors.forename: Dennis C
authors.initials: DC
authors.lastname: Stokes
authors.forename: Mary Ellen B
authors.initials: ME
authors.lastname: Wohl
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Wagener
authors.forename: Warren E
authors.initials: WE
authors.lastname: Regelmann
authors.forename: Charles A
authors.initials: CA
authors.lastname: Johnson
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D002648:Child; D015331:Cohort Studies; D003550:Cystic Fibrosis / Q000175:diagnosis* / Q000453:epidemiology*; D018450:Disease Progression; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D015994:Incidence; D008171:Lung Diseases / Q000175:diagnosis / Q000453:epidemiology*; D008297:Male; D011379:Prognosis; D012307:Risk Factors; D012720:Severity of Illness Index; D017678:Sex Distribution; D013147:Spirometry / Q000379:methods; D013997:Time Factors; D014797:Vital Capacity