Longitudinal change in three brief assessments of SDAT

Previous research has shown that there is considerable interest in the development of brief indices for use in the diagnosis and staging of senile dementia of the Alzheimer's type (SDAT). Examples of such measures include the Blessed Dementia Scale (BDS) and Pfeiffer's Short Portable Mental Status Questionnaire (SPMSQ). A third measure used in the assessment of organic cognitive impairment is the Face-Hand Test (FHT). This study, which was part of a large longitudinal investigation of SDAT, examined the performance of 43 subjects with SDAT and 57 healthy controls over 30 months. The subjects were assessed three times during this period. In addition to the brief measures (BDS, SPMSQ, and FHT) all subjects were rated on a Clinical Dementia Rating (CDR) Scale based on a lengthy clinical interview. The data were analyzed by means of a series of univariate, repeated measures ANOVAs, and discriminant analysis. Results indicate: control scores did not change over time on any of the measures; when classified according to severity of SDAT, different patterns of performance emerged over time for each measure; and it is difficult to accurately predict progression of SDAT from the three scores.