title: Incidence of stroke and seizure in Alzheimer's disease dementia.
abstract: BACKGROUND
  the objective of the study was to estimate and compare the incidence rates of ischaemic and haemorrhagic stroke and seizure among cohorts with and without Alzheimer's disease (AD) dementia.
  
  
  METHODS
  we conducted a retrospective cohort study using electronic medical records (EMRs) from primary care practices that participated in The Health Improvement Network (THIN) in the United Kingdom from 1 January 1990 to 31 July 2009. For each AD-dementia patient, we selected one general population control patient without AD-dementia matched to one AD-dementia patient on year of birth, sex and physician practice.
  
  
  RESULTS
  the AD-dementia cohorts were 68% female and averaged 80 years of age at the start of follow-up. Populations for analysis included 19,902 AD-dementia and matched non-AD-dementia patients with no history of stroke at baseline in which 790 incident cases of stroke occurred, and similarly, 22,084 AD-dementia and matched patients with no history of seizure at baseline in which 286 cases of seizure occurred. After adjusting for risk factors for each outcome, hazard ratios comparing AD-dementia with non-AD-dementia patients indicated higher rates among AD-dementia patients for stroke (HR = 1.29, 95% CI 1.11, 1.50) and seizure (HR = 5.31, 95% CI 3.97, 7.10). For stroke and seizure, the incidence rate ratios comparing AD-dementia patients with non-AD-dementia controls were greatest for the younger age groups. AD-dementia was observed to be a risk factor for both haemorrhagic stroke and seizures. Increasing age was associated with a decrease in relative risk and an increase in absolute risk.
authors.affiliation: Formerly at Pfizer, Collegeville, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Cook
authors.affiliation: Formerly at Pfizer, Collegeville, USA.
authors.forename: Nicole
authors.initials: N
authors.lastname: Baker
authors.affiliation: Healthcore, Southbury, CT, USA.
authors.forename: Stephen
authors.initials: S
authors.lastname: Lanes
authors.affiliation: Swindon, Wiltshire, UK.
authors.forename: Roger
authors.initials: R
authors.lastname: Bullock
authors.affiliation: Wakefield, RI, USA.
authors.forename: Charles
authors.initials: C
authors.lastname: Wentworth
authors.affiliation: Janssen Research and Development, LLC, South San Francisco, CA, USA.
authors.forename: H Michael
authors.initials: HM
authors.lastname: Arrighi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications*; D057286:Electronic Health Records; D005260:Female; D005500:Follow-Up Studies; D015577:Geriatric Assessment / Q000379:methods*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance / Q000379:methods*; D012189:Retrospective Studies; D012307:Risk Factors; D012640:Seizures / Q000453:epidemiology* / Q000209:etiology; D020521:Stroke / Q000453:epidemiology* / Q000209:etiology; D006113:United Kingdom / Q000453:epidemiology
keywords: Alzheimer's disease; THIN; database; older people; seizures; stroke