title: Survival Comparison of Patients With Cystic Fibrosis in Canada and the United States: A Population-Based Cohort Study.
abstract: BACKGROUND
  In 2011, the median age of survival of patients with cystic fibrosis reported in the United States was 36.8 years, compared with 48.5 years in Canada. Direct comparison of survival estimates between national registries is challenging because of inherent differences in methodologies used, data processing techniques, and ascertainment bias.
  
  
  OBJECTIVE
  To use a standardized approach to calculate cystic fibrosis survival estimates and to explore differences between Canada and the United States.
  
  
  METHODS
  Population-based study.
  
  
  METHODS
  42 Canadian cystic fibrosis clinics and 110 U.S. cystic fibrosis care centers.
  
  
  METHODS
  Patients followed in the Canadian Cystic Fibrosis Registry (CCFR) and U.S. Cystic Fibrosis Foundation Patient Registry (CFFPR) between 1990 and 2013.
  
  
  METHODS
  Cox proportional hazards models were used to compare survival between patients followed in the CCFR (n = 5941) and those in the CFFPR (n = 45 448). Multivariable models were used to adjust for factors known to be associated with survival.
  
  
  RESULTS
  Median age of survival in patients with cystic fibrosis increased in both countries between 1990 and 2013; however, in 1995 and 2005, survival in Canada increased at a faster rate than in the United States (P < 0.001). On the basis of contemporary data from 2009 to 2013, the median age of survival in Canada was 10 years greater than in the United States (50.9 vs. 40.6 years, respectively). The adjusted risk for death was 34% lower in Canada than the United States (hazard ratio, 0.66 [95% CI, 0.54 to 0.81]). A greater proportion of patients in Canada received transplants (10.3% vs. 6.5%, respectively [standardized difference, 13.7]). Differences in survival between U.S. and Canadian patients varied according to U.S. patients' insurance status.
  
  
  CONCLUSIONS
  Ascertainment bias due to missing data or nonrandom loss to follow-up might affect the results.
  
  
  CONCLUSIONS
  Differences in cystic fibrosis survival between Canada and the United States persisted after adjustment for risk factors associated with survival, except for private-insurance status among U.S. patients. Differential access to transplantation, increased posttransplant survival, and differences in health care systems may, in part, explain the Canadian survival advantage.
  
  
  BACKGROUND
  U.S. Cystic Fibrosis Foundation.
authors.affiliation: From St. Michael's Hospital, University of Toronto, and The Hospital for Sick Children, Toronto, Ontario, Canada; University of British Columbia, Vancouver, British Columbia, Canada; Cystic Fibrosis Foundation, Bethesda, Maryland; and University of Washington Medical Center, Seattle, Washington.
authors.forename: Anne L
authors.initials: AL
authors.lastname: Stephenson
authors.affiliation: From St. Michael's Hospital, University of Toronto, and The Hospital for Sick Children, Toronto, Ontario, Canada; University of British Columbia, Vancouver, British Columbia, Canada; Cystic Fibrosis Foundation, Bethesda, Maryland; and University of Washington Medical Center, Seattle, Washington.
authors.forename: Jenna
authors.initials: J
authors.lastname: Sykes
authors.affiliation: From St. Michael's Hospital, University of Toronto, and The Hospital for Sick Children, Toronto, Ontario, Canada; University of British Columbia, Vancouver, British Columbia, Canada; Cystic Fibrosis Foundation, Bethesda, Maryland; and University of Washington Medical Center, Seattle, Washington.
authors.forename: Sanja
authors.initials: S
authors.lastname: Stanojevic
authors.affiliation: From St. Michael's Hospital, University of Toronto, and The Hospital for Sick Children, Toronto, Ontario, Canada; University of British Columbia, Vancouver, British Columbia, Canada; Cystic Fibrosis Foundation, Bethesda, Maryland; and University of Washington Medical Center, Seattle, Washington.
authors.forename: Bradley S
authors.initials: BS
authors.lastname: Quon
authors.affiliation: From St. Michael's Hospital, University of Toronto, and The Hospital for Sick Children, Toronto, Ontario, Canada; University of British Columbia, Vancouver, British Columbia, Canada; Cystic Fibrosis Foundation, Bethesda, Maryland; and University of Washington Medical Center, Seattle, Washington.
authors.forename: Bruce C
authors.initials: BC
authors.lastname: Marshall
authors.affiliation: From St. Michael's Hospital, University of Toronto, and The Hospital for Sick Children, Toronto, Ontario, Canada; University of British Columbia, Vancouver, British Columbia, Canada; Cystic Fibrosis Foundation, Bethesda, Maryland; and University of Washington Medical Center, Seattle, Washington.
authors.forename: Kristofer
authors.initials: K
authors.lastname: Petren
authors.affiliation: From St. Michael's Hospital, University of Toronto, and The Hospital for Sick Children, Toronto, Ontario, Canada; University of British Columbia, Vancouver, British Columbia, Canada; Cystic Fibrosis Foundation, Bethesda, Maryland; and University of Washington Medical Center, Seattle, Washington.
authors.forename: Josh
authors.initials: J
authors.lastname: Ostrenga
authors.affiliation: From St. Michael's Hospital, University of Toronto, and The Hospital for Sick Children, Toronto, Ontario, Canada; University of British Columbia, Vancouver, British Columbia, Canada; Cystic Fibrosis Foundation, Bethesda, Maryland; and University of Washington Medical Center, Seattle, Washington.
authors.forename: Aliza K
authors.initials: AK
authors.lastname: Fink
authors.affiliation: From St. Michael's Hospital, University of Toronto, and The Hospital for Sick Children, Toronto, Ontario, Canada; University of British Columbia, Vancouver, British Columbia, Canada; Cystic Fibrosis Foundation, Bethesda, Maryland; and University of Washington Medical Center, Seattle, Washington.
authors.forename: Alexander
authors.initials: A
authors.lastname: Elbert
authors.affiliation: From St. Michael's Hospital, University of Toronto, and The Hospital for Sick Children, Toronto, Ontario, Canada; University of British Columbia, Vancouver, British Columbia, Canada; Cystic Fibrosis Foundation, Bethesda, Maryland; and University of Washington Medical Center, Seattle, Washington.
authors.forename: Christopher H
authors.initials: CH
authors.lastname: Goss
mesh_terms: D002170:Canada / Q000453:epidemiology; D003550:Cystic Fibrosis / Q000401:mortality* / Q000601:surgery; D006801:Humans; D019458:Insurance Coverage; D007348:Insurance, Health; D016040:Lung Transplantation; D016016:Proportional Hazards Models; D012307:Risk Factors; D018855:Single-Payer System; D015996:Survival Rate; D014481:United States / Q000453:epidemiology