title: The prevalence of atrial fibrillation in incident stroke cases and matched population controls in Rochester, Minnesota: changes over three decades.
abstract: OBJECTIVE
  We sought evidence of a change in the prevalence of atrial fibrillation (AF) over a 30-year period among residents of Rochester, Minnesota.
  
  
  BACKGROUND
  Atrial fibrillation is increasingly encountered in clinical practice, but there is limited data on secular trends of AF over time.
  
  
  METHODS
  Within a longitudinal case-control study of ischemic stroke, the prevalence of AF and of selected comorbid conditions among incident stroke cases and age- and gender-matched controls between 1960 and 1989 was determined.
  
  
  RESULTS
  The mean age +/- standard deviation for the 1,871 stroke cases (45% men) and matched controls was 75 +/- 11 years. For cases, age-adjusted estimates of AF prevalence for 1960 to 1969, 1970 to 1979, and 1980 to 1989 were 11%, 13%, and 16%, respectively, for men, and 13%, 16%, and 20% for women. For controls, the rates were 5%, 8%, and 12%, respectively, for men, and 4%, 6%, and 8% for women. Increasing AF prevalence was associated with increasing age (doubling of odds per decade of age in both cases and controls) and calendar time adjusted for age and gender (cases: odds ratio [OR] per 5 years 1.13, 95% confidence interval [CI], 1.05 to 1.22; controls: OR per 5 years 1.24, 95% CI 1.12 to 1.37). The rates of increase with calendar time were significant for cases (p = 0.001) and controls (p < 0.001) and comparable between the genders.
  
  
  CONCLUSIONS
  The prevalence of AF increased significantly in ischemic stroke patients and their controls from 1960 to 1989 in Rochester, Minnesota, independent of age and gender. The rate of increase did not differ significantly between men and women.
authors.affiliation: Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA. tsang.teresa@mayo.edu
authors.forename: Teresa S M
authors.initials: TS
authors.lastname: Tsang
authors.forename: George W
authors.initials: GW
authors.lastname: Petty
authors.forename: Marion E
authors.initials: ME
authors.lastname: Barnes
authors.forename: W Michael
authors.initials: WM
authors.lastname: O'Fallon
authors.forename: Kent R
authors.initials: KR
authors.lastname: Bailey
authors.forename: David O
authors.initials: DO
authors.lastname: Wiebers
authors.forename: JoRean D
authors.initials: JD
authors.lastname: Sicks
authors.forename: Teresa J H
authors.initials: TJ
authors.lastname: Christianson
authors.forename: James B
authors.initials: JB
authors.lastname: Seward
authors.forename: Bernard J
authors.initials: BJ
authors.lastname: Gersh
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000453:epidemiology*; D002545:Brain Ischemia / Q000453:epidemiology*; D016022:Case-Control Studies; D015897:Comorbidity; D004562:Electrocardiography; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D016017:Odds Ratio; D015995:Prevalence; D020521:Stroke / Q000453:epidemiology*