title: Prevalence of dementia in the 'oldest old' of a Dutch community.
abstract: OBJECTIVE
  To estimate the prevalence rate of dementia in subjects 85 years of age and over.
  
  
  METHODS
  A two-phase design with the Mini-Mental State Examination (MMSE) in the screening phase and the Geriatric Mental State Schedule (GMS) in the diagnostic phase.
  
  
  METHODS
  Community survey including subjects in residential care.
  
  
  METHODS
  All (n = 1,259) inhabitants of Leiden, The Netherlands, aged 85 years and over on December 1, 1986. First phase participation rate was 71% (17% dropout due to death); second phase participation rate was 82%.
  
  
  METHODS
  DSM-III diagnosis of dementia without further specification of the etiology of the dementia.
  
  
  RESULTS
  An overall prevalence rate of 23% (95% C.I.: 19%-26%) was found. This included 12% mild dementia, 7% moderate and 4% severe dementia. The prevalence rate was higher among women (24%) than among men (18%). It increased with age from 19% (95% C.I.: 16%-22%) in the group of 85-89 years to 32% (95% C.I.: 26%-39%) in the group of 90-94 years to 41% (95% C.I.: 25%-58%) in the 95+ group.
  
  
  CONCLUSIONS
  A fifth of the 85+ and a third of the 90+ population suffer from dementia with an indication that half of the 95+ population is affected. With the expected steep rise in the number of the oldest old, dementia will stay a major health problem in the near future.
authors.affiliation: Department of Psychiatry Leiden University, The Netherlands.
authors.forename: T J
authors.initials: TJ
authors.lastname: Heeren
authors.forename: A M
authors.initials: AM
authors.lastname: Lagaay
authors.forename: W
authors.initials: W
authors.lastname: Hijmans
authors.forename: H G
authors.initials: HG
authors.lastname: Rooymans
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003704:Dementia / Q000145:classification / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D007406:Interview, Psychological; D008297:Male; D008403:Mass Screening; D008609:Mental Status Schedule; D009426:Netherlands / Q000453:epidemiology; D010352:Patient Dropouts / Q000706:statistics & numerical data; D015995:Prevalence; D012111:Residence Characteristics; D014505:Urban Population