title: Differences in Outcomes between Early and Late Diagnosis of Cystic Fibrosis in the Newborn Screening Era.
abstract: To evaluate children with cystic fibrosis (CF) who had a late diagnosis of CF (LD-CF) despite newborn screening (NBS) and compare their clinical outcomes with children diagnosed after a positive NBS (NBS-CF).
  
  
  
  A retrospective review of patients with LD-CF in New South Wales, Australia, from 1988 to 2010 was performed. LD-CF was defined as NBS-negative (negative immunoreactive trypsinogen or no F508del) or NBS-positive but discharged following sweat chloride < 60 mmol/L. Cases of LD-CF were each matched 1:2 with patients with NBS-CF for age, sex, hospital, and exocrine pancreatic status.
  
  
  
  A total of 45 LD-CF cases were identified (39 NBS-negative and 6 NBS-positive) with 90 NBS-CF matched controls. Median age (IQR) of diagnosis for LD-CF and NBS-CF was 1.35 (0.4-2.8) and 0.12 (0.03-0.2) years, respectively (P <.0001). Estimated incidence of LD-CF was 1 in 45 000 live births. Compared with NBS-CF, LD-CF had more respiratory manifestations at time of diagnosis (66% vs 4%; P <.0001), a higher rate of hospital admission per year for respiratory illness (0.49 vs 0.2; P = .0004), worse lung function (forced expiratory volume in 1 second percentage of predicted, 0.88 vs 0.97; P = .007), and higher rates of chronic colonization with Pseudomonas aeruginosa (47% vs 24%; P = .01). The LD-CF cohort also appeared to be shorter than NBS-CF controls (mean height z-score -0.65 vs -0.03; P = .02).
  
  
  
  LD-CF, despite NBS, seems to be associated with worse health before diagnosis and worse later growth and respiratory outcomes, thus providing further support for NBS programs for CF.
authors.affiliation: School of Women's and Children's Health, Faculty of Medicine, University of New South Wales, Sydney, Australia.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Coffey
authors.affiliation: School of Women's and Children's Health, Faculty of Medicine, University of New South Wales, Sydney, Australia.
authors.forename: Viola
authors.initials: V
authors.lastname: Whitaker
authors.affiliation: School of Women's and Children's Health, Faculty of Medicine, University of New South Wales, Sydney, Australia; Department of General Pediatrics, Sydney Children's Hospital Randwick, Sydney, Australia.
authors.forename: Natalie
authors.initials: N
authors.lastname: Gentin
authors.affiliation: The Children's Hospital at Westmead, Sydney, Australia.
authors.forename: Rosie
authors.initials: R
authors.lastname: Junek
authors.affiliation: Department of Medical Genetics, Sydney Children's Hospital Randwick, Sydney, Australia.
authors.forename: Carolyn
authors.initials: C
authors.lastname: Shalhoub
authors.affiliation: GrowUpWell Priority Research Centre, University of Newcastle, Newcastle, Australia; Department of Gastroenterology, John Hunter Children's Hospital, Newcastle, Australia.
authors.forename: Scott
authors.initials: S
authors.lastname: Nightingale
authors.affiliation: University of Newcastle, Newcastle, Australia; Department of Respiratory Medicine, John Hunter Children's Hospital, Newcastle, Australia.
authors.forename: Jodi
authors.initials: J
authors.lastname: Hilton
authors.affiliation: The Children's Hospital at Westmead, Sydney, Australia; The University of Sydney, Sydney, Australia.
authors.forename: Veronica
authors.initials: V
authors.lastname: Wiley
authors.affiliation: The Children's Hospital at Westmead, Sydney, Australia; The University of Sydney, Sydney, Australia.
authors.forename: Bridget
authors.initials: B
authors.lastname: Wilcken
authors.affiliation: The Children's Hospital at Westmead, Sydney, Australia; The University of Sydney, Sydney, Australia.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Gaskin
authors.affiliation: School of Women's and Children's Health, Faculty of Medicine, University of New South Wales, Sydney, Australia; Department of Gastroenterology, Sydney Children's Hospital Randwick, Sydney, Australia. Electronic address: keith.ooi@unsw.edu.au.
authors.forename: Chee Y
authors.initials: CY
authors.lastname: Ooi
mesh_terms: D000367:Age Factors; D003550:Cystic Fibrosis / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy; D016208:Databases, Factual; D057210:Delayed Diagnosis / Q000009:adverse effects*; D018450:Disease Progression; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D015997:Neonatal Screening / Q000379:methods*; D009517:New South Wales; D017063:Outcome Assessment, Health Care; D011379:Prognosis; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D012737:Sex Factors; D015996:Survival Rate
keywords: Australia; cystic fibrosis transmembrane conductance regulator; growth; lung function