title: Differential diagnosis of dementia: a prospective evaluation of the DAT Inventory.
abstract: OBJECTIVE
  To compare prospectively the concordance between the diagnosis of dementia based on clinical criteria and using the DAT Inventory.
  
  
  METHODS
  A prospective study of 81 consecutive patients referred to a Memory Clinic. Only patients for whom a definitive diagnosis of dementia was established after 8 to 20 months follow-up were retained in the study (n = 76).
  
  
  METHODS
  The sensitivity, specificity, positive and negative predictive values, and overall diagnostic accuracy of the DAT Inventory were calculated. Kappa values were also computed.
  
  
  RESULTS
  Based on all patients (n = 76), sensitivity and specificity were 71% and 95%, respectively, with 98% positive prediction, 56% negative prediction, 78% overall accuracy, and kappa of 0.54. Of 21 cases not meeting NINCDS/ADRDA criteria for DAT, one patient with multi-infarct dementia was misclassified as DAT on the DAT Inventory. Of 55 DAT cases (NINCDS/ADRDA criteria), 16 patients, predominantly very mild or mixed cases, were classified as non-DAT on the DAT Inventory. When mixed, very mild, and borderline cases were excluded (remaining n = 54), DAT Inventory sensitivity increased to 94%, and specificity remained unchanged at 95%, with 97% positive and 91% negative prediction, 94% overall accuracy, and kappa of 0.88.
  
  
  CONCLUSIONS
  In general, scores above the designated cutoff point (> 14/20) on the DAT Inventory are consistent with a clinical diagnosis of DAT (NINCDS/ADRDA criteria). Concordance is best in cases of mild to moderate dementia (Clinical Dementia Rating 1-2). The Inventory is less discriminating as a differential diagnostic instrument in cases of very mild dementia, atypical presentations of DAT, or in cases of mixed pathology.
authors.affiliation: Mercer's Institute for Research on Ageing, St. James' Hospital, Dublin, Ireland.
authors.forename: R F
authors.initials: RF
authors.lastname: Coen
authors.forename: D
authors.initials: D
authors.lastname: O'Mahoney
authors.forename: I
authors.initials: I
authors.lastname: Bruce
authors.forename: B A
authors.initials: BA
authors.lastname: Lawlor
authors.forename: J B
authors.initials: JB
authors.lastname: Walsh
authors.forename: D
authors.initials: D
authors.lastname: Coakley
mesh_terms: D000368:Aged; D003704:Dementia / Q000145:classification / Q000175:diagnosis* / Q000209:etiology; D003937:Diagnosis, Differential; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D010808:Physical Examination; D011446:Prospective Studies; D011581:Psychological Tests / Q000592:standards*; D011594:Psychometrics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed