title: Delirium in the non-demented oldest old in the general population: risk factors and prognosis.
abstract: BACKGROUND
  The oldest old are prone to develop delirium. Studies into risk factors for delirium have been carried out predominantly in younger age groups. The aim of this population-based follow-up study was to investigate the risk factors for delirium requiring medical attention and subsequent prognosis in the non-demented general population aged > or = 85 years.
  
  
  METHODS
  The study included the non-demented subjects in the population-based Vantaa 85+ study. After the 3-year observation period, 199 subjects (91% of those surviving) were re-examined and their medical records were evaluated for episodes of delirium. The subjects were followed up with respect to mortality for another 2 years.
  
  
  RESULTS
  During the 3-year observational period, 20 subjects (10%) had been diagnosed as having had an episode of delirium. A Mini-Mental State Examination score of < 24 (odds ratio (OR) 3.44, confidence interval (CI = 95%) 1.27-9.32) and high systolic blood pressure (OR 3.08, CI 1.08-8.79) were identified as independent risk factors for delirium. The association between the delirium episode and a new diagnosis of dementia was significant ( p = 0.001). The mortality rate was greater among those subjects who experienced delirium than among subjects without this syndrome ( p = 0.008).
  
  
  CONCLUSIONS
  Mild cognitive impairment and high systolic blood pressure were found to be risk factors for delirium requiring medical attention in the general non-demented population aged > or = 85 years. The study also highlights the significant association between delirium and a new dementia diagnosis in this age group.
authors.affiliation: Division of Geriatrics, Department of Public Health and General Practice, University of Kuopio, PO Box 1627, 70211 Kuopio, Finland. terhi.rahkonen@uku.fi
authors.forename: T
authors.initials: T
authors.lastname: Rahkonen
authors.forename: U
authors.initials: U
authors.lastname: Eloniemi-Sulkava
authors.forename: P
authors.initials: P
authors.lastname: Halonen
authors.forename: A
authors.initials: A
authors.lastname: Verkkoniemi
authors.forename: L
authors.initials: L
authors.lastname: Niinistö
authors.forename: I L
authors.initials: IL
authors.lastname: Notkola
authors.forename: R
authors.initials: R
authors.lastname: Sulkava
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003072:Cognition Disorders; D003693:Delirium / Q000175:diagnosis* / Q000453:epidemiology* / Q000209:etiology; D003704:Dementia / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D006973:Hypertension; D015994:Incidence; D008297:Male; D008609:Mental Status Schedule; D016017:Odds Ratio; D011159:Population Surveillance; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors