THE ITALIAN VERSION OF THE ALZHEIMERS-DISEASE ASSESSMENT SCALE (ADAS) - PSYCHOMETRIC AND NORMATIVE CHARACTERISTICS FROM A NORMAL AGED POPULATION

The Alzheimer's Disease Assessment Scale (ADAS) was specifically proposed for the clinical assessment of patients suffering from dementia and is used in different countries. The Italian version of ADAS is presented in this paper together with the description of criteria used in transforming the American edition in the Italian edition. Psychometric and normative data are illustrated and discussed. A sample of 95 healthy volunteers of both sexes ranging in age from 50 to 79 years were recruited from the general population in different parts of Italy and from different social and educational levels. Their performance on the ADAS was analysed by sex, age, and educational level. Results indicated a specific influence of subjects' educational level on the Cognitive Subscale Total Score of ADAS and the need for an adequate correction was evidenced. The two objective measures of memory which constitute, together with the Cognitive Subscale Total Score, the cognitive subscale of ADAS were sensitive to both age and educational level, requiring corrections. The factor structure of the cognitive subscale of ADAS confirms the validity of distinguishing between the clinical-functional scores, which are summarized by the Cognitive Subscale Total Score (CSTS), from those of the objective memory tasks, which are kept separate and used to quantify specific memory characteristics. The main components of the CSTS were 3 factors. The first factor wasrepresented by the congruity of verbal expression, the second factor was related to order comprehension and congruity of execution, and the third factor was related to verbal comprehension. Objective memory scores constituted a factor different from the others.