title: Risk factors for age at initial Pseudomonas acquisition in the cystic fibrosis epic observational cohort.
abstract: BACKGROUND
  Risk factors for initial Pseudomonas aeruginosa (Pa) acquisition, particularly environmental exposures, are poorly understood. We aimed to identify such risk factors in order to inform prevention strategies and identify high-risk populations.
  
  
  METHODS
  The study cohort included all participants in the U.S. EPIC Observational Study who had no prior Pa-positive respiratory cultures (N=889). Cox proportional hazard models were used to test the effects of factors on age at first Pa-positive respiratory culture.
  
  
  RESULTS
  Cystic fibrosis (CF) genotype functional class had an important effect on age at initial Pa acquisition (hazard ratio (HR) comparing minimal to residual CFTR function 2.87 (95% CI 1.88, 4.39)). None of the modifiable risk factors evaluated, including cigarette smoke, hot tub use, breastfeeding, or daycare, was associated with age at Pa acquisition. Similarly, newborn screening was not associated with age at Pa acquisition (HR 0.85, 95% CI 0.66, 1.09). Key associations were validated in a CF Foundation National Patient Registry replication cohort.
  
  
  CONCLUSIONS
  Given the ubiquitous presence of Pa in the environment, it may be that many imposed lifestyle changes will have less impact on age at initial Pa acquisition than genetic determinants.
authors.affiliation: Department of Pediatrics, Seattle Children's Hospital and University of Washington, Seattle, WA 98105, USA. margaret.rosenfeld@seattlechildrens.org
authors.forename: Margaret
authors.initials: M
authors.lastname: Rosenfeld
authors.forename: Julia
authors.initials: J
authors.lastname: Emerson
authors.forename: Sharon
authors.initials: S
authors.lastname: McNamara
authors.forename: Valeria
authors.initials: V
authors.lastname: Thompson
authors.forename: Bonnie W
authors.initials: BW
authors.lastname: Ramsey
authors.forename: Wayne
authors.initials: W
authors.lastname: Morgan
authors.forename: Ronald L
authors.initials: RL
authors.lastname: Gibson
mesh_terms: D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003550:Cystic Fibrosis / Q000453:epidemiology / Q000235:genetics / Q000382:microbiology / Q000503:physiopathology; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics; D004781:Environmental Exposure / Q000145:classification / Q000706:statistics & numerical data; D005006:Ethnicity; D005260:Female; D059647:Gene-Environment Interaction; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015997:Neonatal Screening / Q000379:methods; D016016:Proportional Hazards Models; D011552:Pseudomonas Infections / Q000453:epidemiology / Q000382:microbiology / Q000503:physiopathology; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification*; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000382:microbiology / Q000503:physiopathology; D012307:Risk Factors; D014481:United States / Q000453:epidemiology
chemical_list: D019005:Cystic Fibrosis Transmembrane Conductance Regulator