title: Update on cystic fibrosis epidemiology.
abstract: OBJECTIVE
  With the improving survival of cystic fibrosis (CF) patients, the clinical spectrum of this complex multisystem disease continues to evolve. Epidemiologic studies have provided important insight into the disease course, prognosis, and complications. This review summarizes recent advances in our understanding of predictors of survival and outcome and modifiers of disease in CF. This review is not meant to be comprehensive, but highlights selected studies, many of which have particular relevance to the growing number of older CF patients.
  
  
  RESULTS
  Survival rates of US CF patients improved remarkably over the past 15 years, but most of the improvement was limited to patients 2 to 15 years of age. Both median household income and ambient air pollutants were found to be important modifiers of disease, echoing research reported in other chronic lung diseases. Genotype classified according to functional mutation class was highly associated with outcome (class I, II, and III mutations were associated with the highest mortality). Of the emerging pathogens, B. cepacia complex and B. gladioli are the most prominent. A small but significant percentage of patients have been shown to acquire new B. cepacia complex or B. gladioli strains with time.
  
  
  CONCLUSIONS
  Epidemiologic research in cystic fibrosis continues to inform patient care and clinical research, and to generate new hypotheses regarding pathophysiology. Survival and outcomes continue to improve in this multisystem disease. With continued improving survival, epidemiologic studies will be critical to tracking changes in prognosis and outcome.
authors.affiliation: Department of Medicine, University of Washington Medical Center, Seattle, Washington 98195, USA. goss@u.washington.edu
authors.forename: Christopher H
authors.initials: CH
authors.lastname: Goss
authors.forename: Margaret
authors.initials: M
authors.lastname: Rosenfeld
mesh_terms: D003550:Cystic Fibrosis / Q000453:epidemiology* / Q000401:mortality; D016021:Epidemiologic Studies; D005544:Forecasting; D006801:Humans; D015996:Survival Rate; D014481:United States / Q000453:epidemiology