title: Days of delirium are associated with 1-year mortality in an older intensive care unit population.
abstract: BACKGROUND
  Delirium is a frequent occurrence in older intensive care unit (ICU) patients, but the importance of the duration of delirium in contributing to adverse long-term outcomes is unclear.
  
  
  OBJECTIVE
  To examine the association of the number of days of ICU delirium with mortality in an older patient population.
  
  
  METHODS
  We performed a prospective cohort study in a 14-bed ICU in an urban acute care hospital. The patient population comprised 304 consecutive admissions 60 years of age and older.
  
  
  RESULTS
  The main outcome was 1-year mortality after ICU admission. Patients were assessed daily for delirium with the Confusion Assessment Method for the ICU and a validated chart review method. The median duration of ICU delirium was 3 days (range, 1-46 d). During the follow-up period, 153 (50%) patients died. After adjusting for relevant covariates, including age, severity of illness, comorbid conditions, psychoactive medication use, and baseline cognitive and functional status, the number of days of ICU delirium was significantly associated with time to death within 1 year post-ICU admission (hazard ratio, 1.10; 95% confidence interval, 1.02-1.18).
  
  
  CONCLUSIONS
  Number of days of ICU delirium was associated with higher 1-year mortality after adjustment for relevant covariates in an older ICU population. Investigations should be undertaken to reduce the number of days of ICU delirium and to study the impact of this reduction on important health outcomes, including mortality and functional and cognitive status.
authors.affiliation: Department of Internal Medicine, Pulmonary & Critical Care Section, and the Program on Aging, Yale University School of Medicine, 333 Cedar Street, P.O. Box 208057, New Haven, CT 06520-8057, USA. Margaret.Pisani@yale.edu
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Pisani
authors.forename: So Yeon Joyce
authors.initials: SY
authors.lastname: Kong
authors.forename: Stanislav V
authors.initials: SV
authors.lastname: Kasl
authors.forename: Terrence E
authors.initials: TE
authors.lastname: Murphy
authors.forename: Katy L B
authors.initials: KL
authors.lastname: Araujo
authors.forename: Peter H
authors.initials: PH
authors.lastname: Van Ness
mesh_terms: D000368:Aged; D015331:Cohort Studies; D003237:Connecticut / Q000453:epidemiology; D003693:Delirium / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D015577:Geriatric Assessment / Q000379:methods* / Q000706:statistics & numerical data*; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D053208:Kaplan-Meier Estimate; D008297:Male; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors