title: Risk factors for incident dementia in the very old.
abstract: BACKGROUND
  Several risk factors for dementia, Alzheimer's disease, and cognitive impairment have been established; however, knowledge about risk factors in the very old population (≥85 years) is limited. This study describes the association of several baseline factors with dementia in participants aged ≥85 years, and investigates factors associated with a higher risk of incident dementia over five years.
  
  
  METHODS
  The participants in this population-based cohort study were aged 85, 90, and ≥95 years at baseline (2000-2002). Data were collected during home visits for interviews and testing, from a review of medical records, and/or interviewing the caregiver or next of kin. After five years 212 participants could be followed up concerning incident dementia. Multivariate logistic regression was used.
  
  
  RESULTS
  At baseline, 100/353 (28%) of participants had a dementia diagnosis. Over five years, 71/212 (33.5%) participants developed dementia. Few participants with dementia at baseline remained alive after five years (12%). Depression at the baseline and follow-up time were associated with a higher risk of dementia, odds ratio (OR) (95% CI, p-value) 2.91 (1.37-6.16, 0.005) and 1.61 (1.26-2.05, <0.001) respectively. More social contact and a higher Mini-Mental State Examination score at baseline were associated with lower risk of incident dementia, OR (95% CI, p-value) 0.87 (0.78-0.97, 0.009) and 0.83 (0.74-0.93, 0.001) respectively.
  
  
  CONCLUSIONS
  Prevalence and incidence of dementia are high in very old people and dementia appears to be a fatal disorder. Depression is associated with higher risk of incident dementia over five years whereas more frequent social contacts and a higher MMSE score are associated with lower risk.
authors.affiliation: Aging Research Center (ARC), Karolinska Institutet and Stockholm University, Stockholm, Sweden. Karin.Wallin@ki.se
authors.forename: Karin
authors.initials: K
authors.lastname: Wallin
authors.forename: Gustaf
authors.initials: G
authors.lastname: Boström
authors.forename: Miia
authors.initials: M
authors.lastname: Kivipelto
authors.forename: Yngve
authors.initials: Y
authors.lastname: Gustafson
mesh_terms: D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D003704:Dementia / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D003863:Depression / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D009483:Neuropsychological Tests; D011159:Population Surveillance; D015995:Prevalence; D012306:Risk; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology