title: Pathway from Delirium to Death: Potential In-Hospital Mediators of Excess Mortality.
abstract: OBJECTIVE
  (1) To determine the relationship of incident delirium during hospitalization with 90-day mortality; (2) to identify potential in-hospital mediators through which delirium increases 90-day mortality.
  
  
  METHODS
  Analysis of data from Project Recovery, a controlled clinical trial of a delirium prevention intervention from 1995 to 1998 with follow-up through 2000.
  
  
  METHODS
  Large academic hospital.
  
  
  METHODS
  Patients ≥70 years old without delirium at hospital admission who were at intermediate-to-high risk of developing delirium and received usual care only.
  
  
  METHODS
  (1) Incident delirium; (2) potential mediators of delirium on death including use of restraining devices (physical restraints, urinary catheters), development of hospital acquired conditions (HACs) (falls, pressure ulcers), and exposure to other noxious insults (sleep deprivation, acute malnutrition, dehydration, aspiration pneumonia); (3) death within 90 days of admission.
  
  
  RESULTS
  Among 469 patients, 70 (15%) developed incident delirium. These patients were more likely to experience restraining devices (37% vs 16%, P < .001), HACs (37% vs 12%, P < .001), other noxious insults (63% vs 49%, P = .03), and 90-day mortality (24% vs 6%, P < .001). The inverse probability weighted hazard of death due to delirium was 4.2 (95% CI = 2.8-6.3) in bivariable analyses, increased in a graded manner with additional exposures to restraining devices, HACs, and other noxious insults, and declined by 10.9% after addition of these potential mediator categories, providing evidence of mediation.
  
  
  CONCLUSIONS
  Restraining devices, HACs, and additional noxious insults were more frequent among patients with delirium, increased mortality in a graded manner, and were responsible for a significant percentage of the association of delirium with death. Additional efforts to prevent potential downstream mediators through which delirium increases mortality may help to improve outcomes among hospitalized older adults.
authors.affiliation: Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut.|Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, New Haven, Connecticut.
authors.forename: Kumar
authors.initials: K
authors.lastname: Dharmarajan
authors.affiliation: Department of Research and Development, Philips Healthcare, Baltimore, Maryland.
authors.forename: Sunil
authors.initials: S
authors.lastname: Swami
authors.affiliation: Aging Brain Center, Institute for Aging Research, Hebrew SeniorLife, Boston, Massachusetts.
authors.forename: Ray Y
authors.initials: RY
authors.lastname: Gou
authors.affiliation: Department of Psychiatry and Human Behavior, Department of Neurology, Warren Alpert Medical School, Brown University, Providence, Rhode Island.
authors.forename: Richard N
authors.initials: RN
authors.lastname: Jones
authors.affiliation: Aging Brain Center, Institute for Aging Research, Hebrew SeniorLife, Boston, Massachusetts.|Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.
authors.forename: Sharon K
authors.initials: SK
authors.lastname: Inouye
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003693:Delirium / Q000209:etiology / Q000401:mortality / Q000517:prevention & control*; D005260:Female; D015577:Geriatric Assessment; D006760:Hospitalization; D006801:Humans; D007049:Iatrogenic Disease; D008297:Male; D009026:Mortality; D012149:Restraint, Physical / Q000379:methods
keywords: delirium; geriatrics; hospital care; hospital-acquired conditions; quality of care