title: Cognitive aging and rate of hospitalization in an urban population of older people.
abstract: BACKGROUND
  The association of age-related cognitive change with hospitalization is not well understood.
  
  
  METHODS
  At 3-year intervals for a mean of 8.7 years, 2,273 older residents of a geographically defined urban community underwent cognitive testing from which a global measure was derived. Hospitalization data were obtained from Part A Medicare beneficiary records. The association of level of cognitive function and rate of cognitive decline in each 3-year interval with subsequent rate of hospitalization was assessed using mixed-effects count regression models.
  
  
  RESULTS
  There were 9,091 hospitalizations involving 1,810 of the 2,273 individuals in the cohort (79.6%). Rate of hospitalization increased by 9.7% (95% confidence interval [CI]: 7.2, 12.3) with each additional study year; by 32.7% (95% CI: 26.8, 38.0) for each 1 point lower on the global cognitive measure at the beginning of an observation interval; and by 24.3% (95% CI: 16.6, 32.6) for each 1-point decrease in the global cognitive measure during the previous observation period. These associations persisted after adjustment for comorbidities and exclusion of those with a Mini-Mental State Examination score less than 26.
  
  
  CONCLUSIONS
  Individual differences in trajectories of cognitive aging are associated with subsequent risk of hospitalization.
authors.affiliation: Rush Alzheimer's Disease Center, Rush University Medical Center, 600 South Paulina Street, Suite 1038, Chicago, IL 60612. rwilson@rush.edu.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Wilson
authors.forename: Kumar B
authors.initials: KB
authors.lastname: Rajan
authors.forename: Lisa L
authors.initials: LL
authors.lastname: Barnes
authors.forename: Liesi E
authors.initials: LE
authors.lastname: Hebert
authors.forename: Carlos F
authors.initials: CF
authors.lastname: Mendes de Leon
authors.forename: Denis A
authors.initials: DA
authors.lastname: Evans
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology*; D003071:Cognition / Q000502:physiology*; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D012189:Retrospective Studies; D014481:United States / Q000453:epidemiology; D014505:Urban Population
keywords: Cognitive aging; Epidemiology; Hospital related; Public health.