title: Validation of the 4AT, a new instrument for rapid delirium screening: a study in 234 hospitalised older people.
abstract: OBJECTIVE
  to evaluate the performance of the 4 'A's Test (4AT) in screening for delirium in older patients. The 4AT is a new test for rapid screening of delirium in routine clinical practice.
  
  
  METHODS
  : prospective study of consecutively admitted elderly patients with independent 4AT and reference standard assessments.
  
  
  METHODS
  : an acute geriatrics ward and a department of rehabilitation.
  
  
  METHODS
  two hundred and thirty-six patients (aged ≥70 years) consecutively admitted over a period of 4 months.
  
  
  METHODS
  in each centre, the 4AT was administered by a geriatrician to eligible patients within 24 h of admission. Reference standard delirium diagnosis (DSM-IV-TR criteria) was obtained within 30 min by a different geriatrician who was blind to the 4AT score. The presence of dementia was assessed using the Alzheimer's Questionnaire and the informant section of the Clinical Dementia Rating scale. The main outcome measure was the accuracy of the 4AT in diagnosing delirium.
  
  
  RESULTS
  patients were 83.9 ± 6.1 years old, and the majority were women (64%). Delirium was detected in 12.3% (n = 29), dementia in 31.2% (n = 74) and a combination of both in 7.2% (n = 17). The 4AT had a sensitivity of 89.7% and specificity 84.1% for delirium. The areas under the receiver operating characteristic curves for delirium diagnosis were 0.93 in the whole population, 0.92 in patients without dementia and 0.89 in patients with dementia.
  
  
  CONCLUSIONS
  the 4AT is a sensitive and specific method of screening for delirium in hospitalised older people. Its brevity and simplicity support its use in routine clinical practice.
authors.affiliation: Department of Health Sciences, University of Milano-Bicocca and S. Gerardo Hospital, Geriatric Clinic, Monza, Italy Geriatric Research Group, via Romanino 1, Brescia, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Bellelli
authors.affiliation: Geriatric Research Group, via Romanino 1, Brescia, Italy Department of Rehabilitation and Aged Care, Ancelle Della Carità Hospital, Cremona, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Morandi
authors.affiliation: Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK.
authors.forename: Daniel H J
authors.initials: DH
authors.lastname: Davis
authors.affiliation: Department of Health Sciences, University of Milano-Bicocca and S. Gerardo Hospital, Geriatric Clinic, Monza, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Mazzola
authors.affiliation: Geriatric Research Group, via Romanino 1, Brescia, Italy Department of Rehabilitation and Aged Care, Ancelle Della Carità Hospital, Cremona, Italy.
authors.forename: Renato
authors.initials: R
authors.lastname: Turco
authors.affiliation: Geriatric Research Group, via Romanino 1, Brescia, Italy Department of Rehabilitation and Aged Care, Ancelle Della Carità Hospital, Cremona, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Gentile
authors.affiliation: Edinburgh Delirium Research Group, Geriatric Medicine Unit, University of Edinburgh, Edinburgh, UK.
authors.forename: Tracy
authors.initials: T
authors.lastname: Ryan
authors.affiliation: Edinburgh Delirium Research Group, Geriatric Medicine Unit, University of Edinburgh, Edinburgh, UK.
authors.forename: Helen
authors.initials: H
authors.lastname: Cash
authors.affiliation: Geriatric Research Group, via Romanino 1, Brescia, Italy Department of Rehabilitation and Aged Care, Ancelle Della Carità Hospital, Cremona, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Guerini
authors.affiliation: Geriatric Research Group, via Romanino 1, Brescia, Italy Department of Rehabilitation and Aged Care, Ancelle Della Carità Hospital, Cremona, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Torpilliesi
authors.affiliation: Geriatric Research Group, via Romanino 1, Brescia, Italy Department of Rehabilitation and Aged Care, Ancelle Della Carità Hospital, Cremona, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Del Santo
authors.affiliation: Geriatric Research Group, via Romanino 1, Brescia, Italy Department of Medicine, University of Roma Tor Vergata, Roma, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Trabucchi
authors.affiliation: Department of Health Sciences, University of Milano-Bicocca and S. Gerardo Hospital, Geriatric Clinic, Monza, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Annoni
authors.affiliation: Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK Edinburgh Delirium Research Group, Geriatric Medicine Unit, University of Edinburgh, Edinburgh, UK.
authors.forename: Alasdair M J
authors.initials: AM
authors.lastname: MacLullich
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003693:Delirium / Q000175:diagnosis*; D005260:Female; D015577:Geriatric Assessment / Q000379:methods*; D006801:Humans; D007297:Inpatients / Q000523:psychology*; D008297:Male; D008403:Mass Screening / Q000379:methods*; D017063:Outcome Assessment, Health Care; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires
keywords: cognitive impairment; delirium; delirium detection; dementia; diagnostic accuracy; geriatrics; older people; screening; validation