title: Adelaide stroke incidence study: declining stroke rates but many preventable cardioembolic strokes.
abstract: OBJECTIVE
  Stroke incidence rates are in flux worldwide because of evolving risk factor prevalence, risk factor control, and population aging. Adelaide Stroke Incidence Study was performed to determine the incidence of strokes and stroke subtypes in a relatively elderly population of 148 000 people in the Western suburbs of Adelaide.
  
  
  METHODS
  All suspected strokes were identified and assessed in a 12-month period from 2009 to 2010. Standard definitions for stroke and stroke fatality were used. Ischemic stroke pathogenesis was classified by the Trial of ORG 10172 in Acute Stroke Treatment criteria.
  
  
  RESULTS
  There were 318 stroke events recorded in 301 individuals; 238 (75%) were first-in-lifetime events. Crude incidence rates for first-ever strokes were 161 per 100 000 per year overall (95% confidence interval [CI], 141-183), 176 for men (95% CI, 147-201), and 146 for women (95% CI, 120-176). Adjusted to the world population rates were 76 overall (95% CI, 59-94), 91 for men (95% CI, 73-112), and 61 for women (95% CI, 47-78). The 28-day case fatality rate for first-ever stroke was 19% (95% CI, 14-24); the majority were ischemic (84% [95% CI, 78-88]). Intracerebral hemorrhage comprised 11% (8-16), subarachnoid hemorrhage 3% (1-6), and 3% (1-6) were undetermined. Of the 258 ischemic strokes, 42% (95% CI, 36-49) were of cardioembolic pathogenesis. Atrial fibrillation accounted for 36% of all ischemic strokes, of which 85% were inadequately anticoagulated.
  
  
  CONCLUSIONS
  Stroke incidence in Adelaide has not increased compared with previous Australian studies, despite the aging population. Cardioembolic strokes are becoming a higher proportion of all ischemic strokes.
authors.affiliation: Queen Elizabeth Hospital, Adelaide, Australia. james.leyden@health.sa.gov.au
authors.forename: James M
authors.initials: JM
authors.lastname: Leyden
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Kleinig
authors.forename: Jonathan
authors.initials: J
authors.lastname: Newbury
authors.forename: Sally
authors.initials: S
authors.lastname: Castle
authors.forename: Jennifer
authors.initials: J
authors.lastname: Cranefield
authors.forename: Craig S
authors.initials: CS
authors.lastname: Anderson
authors.forename: Maria
authors.initials: M
authors.lastname: Crotty
authors.forename: Deirdre
authors.initials: D
authors.lastname: Whitford
authors.forename: Jim
authors.initials: J
authors.lastname: Jannes
authors.forename: Andrew
authors.initials: A
authors.lastname: Lee
authors.forename: Jennene
authors.initials: J
authors.lastname: Greenhill
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000453:epidemiology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D020300:Intracranial Hemorrhages / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D012306:Risk; D013021:South Australia / Q000453:epidemiology; D020521:Stroke / Q000453:epidemiology*; D015996:Survival Rate