title: Delirium superimposed on dementia strongly predicts worse outcomes in older rehabilitation inpatients.
abstract: Delirium superimposed on dementia (DSD) is common in many settings. Nonetheless, little is known about the association between DSD and clinical outcomes. The study aim was to evaluate the association between DSD and related adverse outcomes at discharge from rehabilitation and at 1-year follow-up in older inpatients undergoing rehabilitation.
  
  
  
  Prospective cohort study.
  
  
  
  Hospital rehabilitation unit.
  
  
  
  A total of 2642 patients aged 65 years or older admitted between January 2002 and December 2006.
  
  
  
  Dementia predating rehabilitation admission was detected by DSM-III-R criteria. Delirium was diagnosed with the DSM-IV-TR. The primary outcome was that of walking dependence (Barthel Index mobility subitem score of <15) captured as a trajectory from discharge to 1-year follow-up. A mixed-effects multivariate logistic regression model was used to analyze the association between DSD and outcome, after adjusting for relevant covariates. Secondary outcomes were institutionalization and mortality at 1-year follow-up, and logistic regression models were used to analyze these associations.
  
  
  
  The median age was 77 years (interquartile range: 71-83). The prevalence of DSD was 8%, and the prevalence of delirium and dementia alone were 4% and 22%, respectively. DSD at admission was found to be significantly associated with almost a 15-fold increase in the odds of walking dependence (odds ratio [OR] 15.5; 95% Confidence Interval [CI] 5.6-42.7; P < .01). DSD was also significantly associated with a fivefold increase in the risk of institutionalization (OR 5.0; 95% CI 2.8-8.9; P < .01) and an almost twofold increase in the risk of mortality (OR 1.8; 95% CI 1.1-2.8; P = .01).
  
  
  
  DSD is a strong predictor of functional dependence, institutionalization, and mortality in older patients admitted to a rehabilitation setting, suggesting that strategies to detect DSD routinely in practice should be developed and DSD should be included in prognostic models of health care.
authors.affiliation: Department of Rehabilitation and Aged Care of the Ancelle Hospital, Cremona, Italy; Geriatric Research Group, Brescia, Italy. Electronic address: morandi.alessandro@gmail.com.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Morandi
authors.affiliation: Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Davis
authors.affiliation: Pennsylvania State University, University Park, PA.
authors.forename: Donna M
authors.initials: DM
authors.lastname: Fick
authors.affiliation: Department of Rehabilitation and Aged Care of the Ancelle Hospital, Cremona, Italy; Geriatric Research Group, Brescia, Italy.
authors.forename: Renato
authors.initials: R
authors.lastname: Turco
authors.affiliation: Indiana University Center for Aging Research and Regenstrief Institute, Inc, Indianapolis, IN.
authors.forename: Malaz
authors.initials: M
authors.lastname: Boustani
authors.affiliation: Department of Rehabilitation and Aged Care of the Ancelle Hospital, Cremona, Italy; Geriatric Research Group, Brescia, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Lucchi
authors.affiliation: Department of Rehabilitation and Aged Care of the Ancelle Hospital, Cremona, Italy; Geriatric Research Group, Brescia, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Guerini
authors.affiliation: Department of Rehabilitation and Aged Care of the Ancelle Hospital, Cremona, Italy; Geriatric Research Group, Brescia, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Morghen
authors.affiliation: Department of Rehabilitation and Aged Care of the Ancelle Hospital, Cremona, Italy; Geriatric Research Group, Brescia, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Torpilliesi
authors.affiliation: Department of Rehabilitation and Aged Care of the Ancelle Hospital, Cremona, Italy; Geriatric Research Group, Brescia, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Gentile
authors.affiliation: Edinburgh Delirium Research Group, University of Edinburgh, Edinburgh, Scotland.
authors.forename: Alasdair M
authors.initials: AM
authors.lastname: MacLullich
authors.affiliation: Geriatric Research Group, Brescia, Italy; University of Tor Vergata, Rome, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Trabucchi
authors.affiliation: Geriatric Research Group, Brescia, Italy; Department of Health Sciences, University of Milano Bicocca and Geriatric Clinic, San Gerardo Hospital, Monza, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Bellelli
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D003693:Delirium; D003704:Dementia; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization; D006801:Humans; D016015:Logistic Models; D008297:Male; D051346:Mobility Limitation; D016017:Odds Ratio; D011446:Prospective Studies; D012046:Rehabilitation; D016896:Treatment Outcome
keywords: Delirium-superimposed dementia; delirium; dementia; elderly; institutionalization; mobility; mortality