title: Clinical validity of the Mattis Dementia Rating Scale in detecting Dementia of the Alzheimer type. A double cross-validation and application to a community-dwelling sample.
abstract: OBJECTIVE
  To assess the clinical validity of the Dementia Rating Scale (DRS) in detecting patients with dementia of the Alzheimer type (DAT).
  
  
  BACKGROUND
  The DRS is widely used to evaluate cognitive functioning in older adults. Adequate normative data are unavailable; studies addressing the clinical validity of the DRS are limited by small sample sizes.
  
  
  METHODS
  Administered the DRS to 254 outpatients with DAT and 105 healthy elderly subjects. Performed (1) multiple regressions of demographic factors on the DRS and its subscales; (2) derivation of optimal DRS cutoff scores using receiver operating characteristic curves; (3) double cross-validation with stepwise logistic regressions; and (4) application of results to a community-dwelling sample.
  
  
  RESULTS
  Age- and education-adjusted DRS scores were computed. The optimal DRS cutoff score for DAT of 129 or less revealed a sensitivity of 98% and a specificity of 97%. The logistic regressions resulted in a combination of the Memory and Initiation/Perseveration subscales that correctly classified 98% of all subjects, 92% of a subsample of 76 patients with mild DAT, and 100% of the 51 patients with autopsy-confirmed DAT. The resultant equation was then applied to a community-dwelling sample (238 healthy elderly subjects and 44 patients with DAT): 91% of patients and 93% of normal subjects were correctly classified. Of an additional 77 individuals with questionable DAT, 43 were classified as demented and 34 were classified as nondemented.
  
  
  CONCLUSIONS
  The DRS is a clinically valid psychometric test for the detection of DAT. The Memory and Initiation/Perseveration subscales are its best discriminative indexes for an abbreviated version.
authors.affiliation: Department of Psychiatry, University of California, San Diego School of Medicine, USA.
authors.forename: A U
authors.initials: AU
authors.lastname: Monsch
authors.forename: M W
authors.initials: MW
authors.lastname: Bondi
authors.forename: D P
authors.initials: DP
authors.lastname: Salmon
authors.forename: N
authors.initials: N
authors.lastname: Butters
authors.forename: L J
authors.initials: LJ
authors.lastname: Thal
authors.forename: L A
authors.initials: LA
authors.lastname: Hansen
authors.forename: W C
authors.initials: WC
authors.lastname: Wiederholt
authors.forename: D A
authors.initials: DA
authors.lastname: Cahn
authors.forename: M R
authors.initials: MR
authors.lastname: Klauber
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D011569:Psychiatric Status Rating Scales; D012372:ROC Curve; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity