Early detection of dementia in clinical practice

Early identification of dementia and possible risk factors is a critical issue. The Basic Italian Cognitive Questionnaire (BICQ) is designed as a routine instrument for screening patients with initial cognitive impairment in daily practice. It is devoted to the general physician who needs a tool for deciding whether a subject deserves further diagnostic investigation in specialised centres. The administration of BICQ is easy, fast and does not require any training, since it is composed of 12 simple and ecologic questions referring to daily life. The discriminant analysis, a predictive model that generates a function based on linear combinations of the predictor variables, provided the best discrimination between controls with respect to the group of deteriorated patients. According to the classification function coefficients, the questionnaire score predicted correctly 100% of normal subjects and 85% of patients with cognitive impairment. Moreover, the receiving operating characteristics (ROC) analysis showed that the highest sensitivity and specificity were obtained at the cut-off value of 10. Thus, a ≤10 score was indicative of a possible cognitive impairment requiring further diagnostic work-up. Among 963 randomly selected subjects from the general population over 50 years of age, 130 subjects (13.5%) had a score ≤10. A complete diagnostic assessment was carried out in 103 of them. Forty-one (40%) resulted cognitively normal; 34 (33%) fulfilled the diagnostic criteria for mild cognitive impairment (MCI); 28 (27%) were diagnosed as demented.