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
A. U. Monsch, M. W. Bondi, D. P. Salmon, N. Butters, L. J. Thal, L. A. Hansen, W. C. Wiederholt, D. A. Cahn and M. R. Klauber
Department of Psychiatry, University of California, San Diego School of Medicine, USA.
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. DESIGN
AND 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.
