title: Alzheimer disease and risk of stroke: a population-based cohort study.
abstract: OBJECTIVE
  To investigate the risk of stroke in patients clinically diagnosed with Alzheimer disease (AD) compared with non-AD patients with similar vascular risk factors.
  
  
  METHODS
  Using data obtained from Taiwan's National Health Insurance Research Database, we evaluated the risk of ischemic stroke (IS) and intracerebral hemorrhage (ICH) in patients with AD (n = 980) who had no history of stroke, vascular dementia, or other cerebral degenerative diseases. Our evaluation period spanned from 2000 to 2010. We performed a 1:5 case-control matched analysis, in which cases were matched to controls according to their estimated propensity scores, which were based on demographics and existing vascular risk factors. This approach reduced selection bias. Cox proportional hazards regression analysis was then used to estimate the risk of IS and ICH in AD, conditional for matched pairs.
  
  
  RESULTS
  Overall, patients with AD had a higher risk of IS and ICH than those without AD. The incidence of IS in AD cases and non-AD controls was 37.8 and 23.2 per 1,000 person-years, with an adjusted hazard ratio of 1.66 (95% confidence interval, 1.37-2.01, p < 0.001). The incidence of ICH in AD cases and non-AD controls was 5.2 and 3.0 per 1,000 person-years, with an adjusted hazard ratio of 1.70 (95% confidence interval, 1.03-2.79, p = 0.037).
  
  
  CONCLUSIONS
  Clinical diagnosis of AD is associated with considerably increased risk of stroke development.
authors.affiliation: Department of Neurology, Shuang Ho Hospital, Taipei Medical University, Taiwan.
authors.forename: Nai-Fang
authors.initials: NF
authors.lastname: Chi
authors.forename: Li-Nien
authors.initials: LN
authors.lastname: Chien
authors.forename: Hsiao-Lun
authors.initials: HL
authors.lastname: Ku
authors.forename: Chaur-Jong
authors.initials: CJ
authors.lastname: Hu
authors.forename: Hung-Yi
authors.initials: HY
authors.lastname: Chiou
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications* / Q000453:epidemiology*; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D020521:Stroke / Q000150:complications* / Q000453:epidemiology*; D013624:Taiwan / Q000453:epidemiology