title: Hospitalization and Alzheimer's disease: results from a community-based study.
abstract: BACKGROUND
  Prior studies offer conflicting findings on whether Alzheimer's disease (AD) is associated with an increased risk of hospitalization.
  
  
  METHODS
  We investigated AD and hospitalization in the Washington Heights-Inwood Columbia Aging Project (WHICAP), a community-based study of 2,334 elders in New York City. In 1996, an electronic medical records system was established that allows an e-mail alert to be sent to the research team whenever WHICAP subjects are admitted to Columbia-Presbyterian Medical Center (CPMC), the site of hospital care for the majority of subjects.
  
  
  RESULTS
  Of the WHICAP cohort, 13.1% was admitted to CPMC in 21 months of follow-up; 17.5% of AD patients and 11.9% of unaffected subjects were admitted (p<.01). Multivariate logistic regression models showed that more advanced AD (Clinical Dementia Rating scale 3+) was a significant risk factor for hospitalization independently of age, gender, education, comorbid medical conditions, and death in the follow-up period (OR 2.3; 95% CI: 1.1, 4.6); subjects with mild or moderate AD did not show a significantly elevated risk. The prevalence of psychiatric symptoms did not differ between AD subjects who were hospitalized in the reporting period and AD subjects who were not hospitalized. Infectious disease was a more common discharge diagnosis for subjects with AD (p<.05).
  
  
  CONCLUSIONS
  In this community-based cohort, subjects with severe AD were more likely to be hospitalized than unaffected subjects. The increased use of hospital care by these AD patients appears to be specific to AD but is not a result of psychiatric morbidity or end-of-life care. Rather, a greater risk of medical complications that require hospital care, especially infections, appears to be characteristic of severe AD.
authors.affiliation: Gertrude H. Sergievsky Center and Department of Medical Informatics, Columbia University, New York, NY 10032, USA. sma10@columbia.edu
authors.forename: S M
authors.initials: SM
authors.lastname: Albert
authors.forename: R
authors.initials: R
authors.lastname: Costa
authors.forename: C
authors.initials: C
authors.lastname: Merchant
authors.forename: S
authors.initials: S
authors.lastname: Small
authors.forename: R A
authors.initials: RA
authors.lastname: Jenders
authors.forename: Y
authors.initials: Y
authors.lastname: Stern
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000145:classification / Q000453:epidemiology*; D002423:Cause of Death; D015331:Cohort Studies; D003141:Communicable Diseases / Q000453:epidemiology; D015897:Comorbidity; D003195:Computer Communication Networks; D004522:Educational Status; D005260:Female; D005500:Follow-Up Studies; D006753:Hospital Records; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D009519:New York City / Q000453:epidemiology; D015995:Prevalence; D012307:Risk Factors; D012737:Sex Factors; D014504:Urban Health / Q000706:statistics & numerical data