title: Characterization of dementia and Alzheimer's disease in an older population: updated incidence and life expectancy with and without dementia.
abstract: OBJECTIVE
  We estimated dementia incidence rates, life expectancies with and without dementia, and percentage of total life expectancy without dementia.
  
  
  METHODS
  We studied 3605 members of Group Health (Seattle, WA) aged 65 years or older who did not have dementia at enrollment to the Adult Changes in Thought study between 1994 and 2008. We estimated incidence rates of Alzheimer's disease and dementia, as well as life expectancies with and without dementia, defined as the average number of years one is expected to live with and without dementia, and percentage of total life expectancy without dementia.
  
  
  RESULTS
  Dementia incidence increased through ages 85 to 89 years (74.2 cases per 1000 person-years) and 90 years or older (105 cases per 1000 person-years). Life expectancy without dementia and percentage of total life expectancy without dementia decreased with age. Life expectancy with dementia was longer in women and people with at least a college degree. Percentage of total life expectancy without dementia was greater in younger age groups, men, and those with more education.
  
  
  CONCLUSIONS
  Efforts to delay onset of dementia, if successful, would likely benefit older adults of all ages.
authors.affiliation: Sarah E. Tom is with the Pharmaceutical Health Services Research Department, School of Pharmacy, University of Maryland, Baltimore. Rebecca A. Hubbard and Eric B. Larson are with the Group Health Research Institute, Group Health Cooperative, Seattle, WA. Paul K. Crane and Eric B. Larson are with the Department of Medicine, University of Washington, Seattle. Sebastien J. Haneuse is with the Department of Biostatistics, School of Public Health, Harvard University, Cambridge, MA. James Bowen is with the Swedish Neuroscience Institute, Seattle, WA. Wayne C. McCormick is with the Harborview Medical Center, Seattle, WA. Susan McCurry is with Psychosocial and Community Health, School of Nursing, University of Washington.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Tom
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Hubbard
authors.forename: Paul K
authors.initials: PK
authors.lastname: Crane
authors.forename: Sebastien J
authors.initials: SJ
authors.lastname: Haneuse
authors.forename: James
authors.initials: J
authors.lastname: Bowen
authors.forename: Wayne C
authors.initials: WC
authors.lastname: McCormick
authors.forename: Susan
authors.initials: S
authors.lastname: McCurry
authors.forename: Eric B
authors.initials: EB
authors.lastname: Larson
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000453:epidemiology* / Q000401:mortality; D003704:Dementia / Q000453:epidemiology* / Q000401:mortality; D004522:Educational Status; D005260:Female; D006801:Humans; D015994:Incidence; D008017:Life Expectancy; D008297:Male; D012307:Risk Factors; D012737:Sex Factors; D014861:Washington / Q000453:epidemiology