title: Diagnosing delirium in older emergency department patients: validity and reliability of the delirium triage screen and the brief confusion assessment method.
abstract: OBJECTIVE
  Delirium is a common form of acute brain dysfunction with prognostic significance. Health care professionals caring for older emergency department (ED) patients miss delirium in approximately 75% of cases. This error results from a lack of available measures that can be performed rapidly enough to be incorporated into clinical practice. Therefore, we developed and evaluated a novel 2-step approach to delirium surveillance for the ED.
  
  
  METHODS
  This prospective observational study was conducted at an academic ED in patients aged 65 years or older. A research assistant and physician performed the Delirium Triage Screen (DTS), designed to be a highly sensitive rule-out test, and the Brief Confusion Assessment Method (bCAM), designed to be a highly specific rule-in test for delirium. The reference standard for delirium was a comprehensive psychiatrist assessment using Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria. All assessments were independently conducted within 3 hours of one another. Sensitivities, specificities, and likelihood ratios with their 95% confidence intervals (95% CIs) were calculated.
  
  
  RESULTS
  Of 406 enrolled patients, 50 (12.3%) had delirium diagnosed by the psychiatrist reference standard. The DTS was 98.0% sensitive (95% CI 89.5% to 99.5%), with an expected specificity of approximately 55% for both raters. The DTS's negative likelihood ratio was 0.04 (95% CI 0.01 to 0.25) for both raters. As the complement, the bCAM had a specificity of 95.8% (95% CI 93.2% to 97.4%) and 96.9% (95% CI 94.6% to 98.3%) and a sensitivity of 84.0% (95% CI 71.5% to 91.7%) and 78.0% (95% CI 64.8% to 87.2%) when performed by the physician and research assistant, respectively. The positive likelihood ratios for the bCAM were 19.9 (95% CI 12.0 to 33.2) and 25.2 (95% CI 13.9 to 46.0), respectively. If the research assistant DTS was followed by the physician bCAM, the sensitivity of this combination was 84.0% (95% CI 71.5% to 91.7%) and specificity was 95.8% (95% CI 93.2% to 97.4%). If the research assistant performed both the DTS and bCAM, this combination was 78.0% sensitive (95% CI 64.8% to 87.2%) and 97.2% specific (95% CI 94.9% to 98.5%). If the physician performed both the DTS and bCAM, this combination was 82.0% sensitive (95% CI 69.2% to 90.2%) and 95.8% specific (95% CI 93.2% to 97.4%).
  
  
  CONCLUSIONS
  In older ED patients, this 2-step approach (highly sensitive DTS followed by highly specific bCAM) may enable health care professionals, regardless of clinical background, to efficiently screen for delirium. Larger, multicenter trials are needed to confirm these findings and to determine the effect of these assessments on delirium recognition in the ED.
authors.affiliation: Center for Quality Aging, Vanderbilt University School of Medicine, Nashville, TN; Department of Emergency Medicine, Vanderbilt University School of Medicine, Nashville, TN. Electronic address: jin.h.han@vanderbilt.edu.
authors.forename: Jin H
authors.initials: JH
authors.lastname: Han
authors.affiliation: Department of Psychiatry, Vanderbilt University School of Medicine, Nashville, TN.
authors.forename: Amanda
authors.initials: A
authors.lastname: Wilson
authors.affiliation: Center for Quality Aging, Vanderbilt University School of Medicine, Nashville, TN; Department of Medicine, Division of General Internal Medicine and Public Health, Vanderbilt University School of Medicine, Nashville, TN; Center for Health Services Research, Vanderbilt University School of Medicine, Nashville, TN; Geriatric Research, Education, and Clinical Center (GRECC), Department of Veterans Affairs Medical Center, Tennessee Valley Health Care Center, Nashville, TN.
authors.forename: Eduard E
authors.initials: EE
authors.lastname: Vasilevskis
authors.affiliation: Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, TN.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Shintani
authors.affiliation: Center for Quality Aging, Vanderbilt University School of Medicine, Nashville, TN; Department of Medicine, Division of General Internal Medicine and Public Health, Vanderbilt University School of Medicine, Nashville, TN; Center for Health Services Research, Vanderbilt University School of Medicine, Nashville, TN; Geriatric Research, Education, and Clinical Center (GRECC), Department of Veterans Affairs Medical Center, Tennessee Valley Health Care Center, Nashville, TN.
authors.forename: John F
authors.initials: JF
authors.lastname: Schnelle
authors.affiliation: Department of Medicine, Division of General Internal Medicine and Public Health, Vanderbilt University School of Medicine, Nashville, TN; Center for Health Services Research, Vanderbilt University School of Medicine, Nashville, TN; Geriatric Research, Education, and Clinical Center (GRECC), Department of Veterans Affairs Medical Center, Tennessee Valley Health Care Center, Nashville, TN.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Dittus
authors.affiliation: Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, TN.
authors.forename: Amy J
authors.initials: AJ
authors.lastname: Graves
authors.affiliation: Department of Emergency Medicine, Vanderbilt University School of Medicine, Nashville, TN.
authors.forename: Alan B
authors.initials: AB
authors.lastname: Storrow
authors.affiliation: Department of Psychiatry, Vanderbilt University School of Medicine, Nashville, TN.
authors.forename: John
authors.initials: J
authors.lastname: Shuster
authors.affiliation: Center for Quality Aging, Vanderbilt University School of Medicine, Nashville, TN; Center for Health Services Research, Vanderbilt University School of Medicine, Nashville, TN; Department of Internal Medicine, Division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University School of Medicine, Nashville, TN; Geriatric Research, Education, and Clinical Center (GRECC), Department of Veterans Affairs Medical Center, Tennessee Valley Health Care Center, Nashville, TN.
authors.forename: E Wesley
authors.initials: EW
authors.lastname: Ely
mesh_terms: D000368:Aged; D003221:Confusion / Q000175:diagnosis*; D003693:Delirium / Q000175:diagnosis*; D003937:Diagnosis, Differential; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D014218:Triage
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