title: Validation study of the European Portuguese version of the Confusion Assessment Method (CAM).
abstract: BACKGROUND
  The Confusion Assessment Method (CAM) is the most widely used delirium screening instrument. The aim of this study was to evaluate the reliability and validity of the European Portuguese version of CAM.
  
  
  METHODS
  The sample included elderly patients (≥65 years), admitted for at least 48 h, into two intermediate care units (ICMU) of Intensive Medicine and Surgical Services in a university hospital. Exclusion criteria were: score ≤11 on the Glasgow Coma Scale (GCS), blindness/deafness, inability to communicate and to speak Portuguese. For concurrent validity, a blinded assessment was conducted by a psychiatrist (DSM-IV-TR, as a reference standard) and by a trained researcher (CAM). This instrument was also compared with other cognitive measures to evaluate convergent validity. Inter-rater reliability was also assessed.
  
  
  RESULTS
  In this sample (n = 208), 25% (n = 53) of the patients had delirium, according to DSM-IV-TR. Using this reference standard, the CAM had a moderate sensitivity of 79% and an excellent specificity of 99%. The positive predictive value was 95%, indicating a strong ability to confirm delirium with a positive test result, and the negative predictive value was lower (93%). Good convergent validity was also found, in particular with Mini-Mental State Examination (MMSE) (rs = -0.676; p ≤0.01) and Digit Span Test (DST) forward (rs = -0.605; p ≤0.01), as well as a high inter-rater reliability (diagnostic k = 1.00; single items' k between 0.65 and 1.00).
  
  
  CONCLUSIONS
  Robust results on concurrent and convergent validity and good reliability were achieved. This version was shown to be a valid and reliable instrument for delirium detection in elderly patients hospitalized in intermediate care units.
authors.affiliation: Research and Education Unit on Aging/UNIFAI-University of Porto,Rua Jorge de Viterbo Ferreira,nº 228,4050-313 Porto,Portugal.
authors.forename: Sónia
authors.initials: S
authors.lastname: Martins
authors.affiliation: UCISU,Intensive Medicine Service,CHSJ,Porto. Al. Hernâni Monteiro,4200-319 Porto,Portugal.
authors.forename: Carla
authors.initials: C
authors.lastname: Lourenço
authors.affiliation: Department of Surgery,Faculty of Medicine,University of Porto,Al. Hernâni Monteiro,4200-319 Porto,Portugal.
authors.forename: João
authors.initials: J
authors.lastname: Pinto-de-Sousa
authors.affiliation: UCISU,Intensive Medicine Service,CHSJ,Porto. Al. Hernâni Monteiro,4200-319 Porto,Portugal.
authors.forename: Filipe
authors.initials: F
authors.lastname: Conceição
authors.affiliation: Intensive Medicine and Emergency Autonomous Management Unit,CHSJ. Faculty of Medicine,University of Porto,Al. Hernâni Monteiro,4200-319 Porto,Portugal.
authors.forename: José Artur
authors.initials: JA
authors.lastname: Paiva
authors.affiliation: Psychological Assessment Laboratory. CINEICC. Faculty of Psychology and Educational Sciences,University of Coimbra,Rua do Colégio Novo. Apartado 6153,3001-802 Coimbra,Portugal.
authors.forename: Mário R
authors.initials: MR
authors.lastname: Simões
authors.affiliation: UNIFAI/CINTESIS Research Unit. Faculty of Medicine,University of Porto,Clinic of Psychiatry and Mental Health,CHSJ,Porto. Al. Hernâni Monteiro,4200-319 Porto,Portugal.
authors.forename: Lia
authors.initials: L
authors.lastname: Fernandes
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003221:Confusion / Q000175:diagnosis* / Q000523:psychology; D003693:Delirium / Q000175:diagnosis / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation; D011569:Psychiatric Status Rating Scales; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: reliability