title: The Confusion Assessment Method for the ICU-7 Delirium Severity Scale: A Novel Delirium Severity Instrument for Use in the ICU.
abstract: OBJECTIVE
  Delirium severity is independently associated with longer hospital stays, nursing home placement, and death in patients outside the ICU. Delirium severity in the ICU is not routinely measured because the available instruments are difficult to complete in critically ill patients. We designed our study to assess the reliability and validity of a new ICU delirium severity tool, the Confusion Assessment Method for the ICU-7 delirium severity scale.
  
  
  METHODS
  Observational cohort study.
  
  
  METHODS
  Medical, surgical, and progressive ICUs of three academic hospitals.
  
  
  METHODS
  Five hundred eighteen adult (≥ 18 yr) patients.
  
  
  METHODS
  None.
  
  
  RESULTS
  Patients received the Confusion Assessment Method for the ICU, Richmond Agitation-Sedation Scale, and Delirium Rating Scale-Revised-98 assessments. A 7-point scale (0-7) was derived from responses to the Confusion Assessment Method for the ICU and Richmond Agitation-Sedation Scale items. Confusion Assessment Method for the ICU-7 showed high internal consistency (Cronbach's α = 0.85) and good correlation with Delirium Rating Scale-Revised-98 scores (correlation coefficient = 0.64). Known-groups validity was supported by the separation of mechanically ventilated and nonventilated assessments. Median Confusion Assessment Method for the ICU-7 scores demonstrated good predictive validity with higher odds (odds ratio = 1.47; 95% CI = 1.30-1.66) of in-hospital mortality and lower odds (odds ratio = 0.8; 95% CI = 0.72-0.9) of being discharged home after adjusting for age, race, gender, severity of illness, and chronic comorbidities. Higher Confusion Assessment Method for the ICU-7 scores were also associated with increased length of ICU stay (p = 0.001).
  
  
  CONCLUSIONS
  Our results suggest that Confusion Assessment Method for the ICU-7 is a valid and reliable delirium severity measure among ICU patients. Further research comparing it to other delirium severity measures, its use in delirium efficacy trials, and real-life implementation is needed to determine its role in research and clinical practice.
authors.affiliation: 1Indiana University School of Medicine, Indianapolis, IN. 2Indiana University Center for Aging Research, Indianapolis, IN. 3Regenstrief Institute, Inc., Indianapolis, IN. 4Indiana University Center for Health Innovation and Implementation Science, Indiana Clinical and Translational Sciences Institute, Indianapolis, IN. 5Eskenazi Health, Indianapolis, IN. 6Department of Pharmacy Practice, Purdue University College of Pharmacy, West Lafayette, IN. 7Nursing Research Division, Department of Nursing, Mayo Clinic, Rochester, MN.
authors.forename: Babar A
authors.initials: BA
authors.lastname: Khan
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Perkins
authors.forename: Sujuan
authors.initials: S
authors.lastname: Gao
authors.forename: Siu L
authors.initials: SL
authors.lastname: Hui
authors.forename: Noll L
authors.initials: NL
authors.lastname: Campbell
authors.forename: Mark O
authors.initials: MO
authors.lastname: Farber
authors.forename: Linda L
authors.initials: LL
authors.lastname: Chlan
authors.forename: Malaz A
authors.initials: MA
authors.lastname: Boustani
mesh_terms: D000328:Adult; D000368:Aged; D001288:Attention; D003243:Consciousness; D003693:Delirium / Q000175:diagnosis*; D005260:Female; D006785:Hospitals, University; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D010351:Patient Discharge; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales / Q000592:standards*; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D012959:Socioeconomic Factors