title: The delirium observation screening scale recognizes delirium early after cardiac surgery.
abstract: BACKGROUND
  Delirium or acute confusion is a temporary mental disorder which occurs frequently among hospitalized elderly patients. Patients who undergo cardiac surgery have an increased risk of developing delirium. Prevention or early recognition of delirium is essential. The Delirium Observation Screening (DOS) scale was developed to facilitate early recognition of delirium by nurses' observations during routine clinical care.
  
  
  OBJECTIVE
  The aim of this study was to validate the DOS scale in accordance with the diagnosis of the psychiatrist, using the DSM-IV criteria as the gold standard.
  
  
  METHODS
  In this observational study, the DOS scale was used to assess whether 112 patients who underwent elective cardiac surgery had developed a postoperative delirium. The psychiatrist was consulted to confirm or refute the diagnosis delirium. Wilcoxon's Rank Sum Test was utilized to compare patients with and without delirium on duration of hospital stay. A Receiver Operating Characteristic Curve of the DOS scale was constructed with accompanying Area Under the Curve (AUC).
  
  
  RESULTS
  Based on the diagnosis of the psychiatrist, the incidence of delirium following cardiac surgery was 21.4% and the mean duration of delirium was two and a half days. The time to discharge was 11 days longer in patients with delirium. In 27 of the 112 patients a DOS score of >or=3 was found, that indicates delirium. The sensitivity and specificity of the DOS scale was 100% and 96.6% respectively. The AUC was 0.98.
  
  
  CONCLUSIONS
  The DOS scale is a very good instrument to facilitate early recognition of delirium by nurses' observation of patients who undergo cardiac surgery. Early recognition will expedite good postoperative management such as implementation of appropriate interventions, and may decrease negative consequences caused by postoperative delirium.
authors.affiliation: Department of Thoracic Surgery, Medisch Spectrum Twente, 7500 KA Enschede, the Netherlands. koster.sandra@noknok.nl
authors.forename: Sandra
authors.initials: S
authors.lastname: Koster
authors.forename: Ab G
authors.initials: AG
authors.lastname: Hensens
authors.forename: Frits G J
authors.initials: FG
authors.lastname: Oosterveld
authors.forename: Arie
authors.initials: A
authors.lastname: Wijma
authors.forename: Job
authors.initials: J
authors.lastname: van der Palen
mesh_terms: D000368:Aged; D006348:Cardiac Surgical Procedures / Q000009:adverse effects* / Q000451:nursing / Q000706:statistics & numerical data; D003693:Delirium / Q000175:diagnosis* / Q000453:epidemiology / Q000451:nursing*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000592:standards* / Q000706:statistics & numerical data; D009730:Nursing Assessment / Q000592:standards* / Q000706:statistics & numerical data; D013527:Perioperative Nursing / Q000379:methods; D011182:Postoperative Care / Q000379:methods / Q000451:nursing; D011183:Postoperative Complications / Q000175:diagnosis / Q000453:epidemiology / Q000451:nursing; D015995:Prevalence; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity