title: Impaired arousal at initial presentation predicts 6-month mortality: an analysis of 1084 acutely ill older patients.
abstract: OBJECTIVE
  Impaired arousal signifies underlying brain dysfunction, but its clinical significance outside the intensive care unit remains unclear. We sought to determine if impaired arousal at initial presentation was associated with higher 6-month mortality and if this relationship existed in the absence of delirium.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  An emergency department located within an academic, tertiary care hospital.
  
  
  METHODS
  A total of 1084 noncomatose patients who were aged 65 years or older.
  
  
  METHODS
  The Richmond Agitation-Sedation Scale (RASS) is a 10-second arousal scale; a score of 0 indicates normal arousal. Cox proportional hazard regression was performed adjusting for patient characteristics, admission status, and psychoactive medication administration. To determine if impaired arousal in the absence of delirium was associated with 6-month mortality, Cox proportional hazard regression was performed in a subset of 406 patients who received a psychiatric assessment; the inverse weighted propensity score method was used to minimize residual confounding. Hazard ratios (HR) with their 95% confidence intervals (95% CI) were reported.
  
  
  RESULTS
  Patients with impaired arousal were 73% more likely to die within 6 months (HR: 1.73, 95% CI: 1.21-2.49). Even in the absence of delirium, patients with an abnormal RASS were more likely to die within 6 months (HR: 2.20, 95% CI: 1.10-4.41).
  
  
  CONCLUSIONS
  Impaired arousal at initial presentation is an independent predictor of death within 6 months in a diverse group of acutely ill older patients, even in the absence of delirium. Routine RASS assessment of arousal during clinical care may be warranted as it correlates with prognosis.
authors.affiliation: Center for Quality Aging, Vanderbilt University School of Medicine, Nashville, Tennessee; Department of Emergency Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee.
authors.forename: Jin H
authors.initials: JH
authors.lastname: Han
authors.forename: Eduard E
authors.initials: EE
authors.lastname: Vasilevskis
authors.forename: Ayumi
authors.initials: A
authors.lastname: Shintani
authors.forename: Amy J
authors.initials: AJ
authors.lastname: Graves
authors.forename: John F
authors.initials: JF
authors.lastname: Schnelle
authors.forename: Robert S
authors.initials: RS
authors.lastname: Dittus
authors.forename: James S
authors.initials: JS
authors.lastname: Powers
authors.forename: Amanda
authors.initials: A
authors.lastname: Wilson
authors.forename: Alan B
authors.initials: AB
authors.lastname: Storrow
authors.forename: E Wesley
authors.initials: EW
authors.lastname: Ely
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D001143:Arousal; D015331:Cohort Studies; D004632:Emergency Medical Services / Q000639:trends*; D005260:Female; D006801:Humans; D008297:Male; D009026:Mortality / Q000639:trends*; D011237:Predictive Value of Tests; D011446:Prospective Studies