STAGING OF MENTAL IMPAIRMENT BY MEANS OF DISCRIMINANT ANALYSIS.

By the use of discriminant analysis it was possible to obtain from a wide neuropsychological battery a few psychometric tests able to stage five levels of mental impairment in 70 healthy and demented elderly subjects, according to two canonical variables. The tests maximally discriminant among the groups were: Personal Memory items of Blessed Dementia Scale, Five Words Recall after 24h, paired Words Acquisition, Information/Orientation and Mental Ability items of Clifton Assessment Schedule. The accuracy of the prediction rule was evaluated on a validation set of patients. The short battery made it possible to classify correctly 90% of subjects and to follow easily the course of mental decline. The agreement between observed and predicted groups was 0.93 as calculated by the weighted kappa. We emphasize the role of discriminate analysis in the evaluation of neuropsychological batteries for diagnostic purposes. [ABSTRACT FROM AUTHOR]