THE VALIDITY OF PSYCHOMETRIC INSTRUMENTS FOR DETECTION OF DEMENTIA INTHE ELDERLY GENERAL-POPULATION

Objective. To compare the validity of different instruments for screen ing and diagnosis of dementia and to provide threshold scores for thes e purposes, ie screening focusing on a high sensitivity and diagnosis focusing on a high specificity. Setting. 287 subjects from a general p opulation sample who had completed more than one of these psychometric tests. Method's. The performances of the Structured Interview for the Diagnosis of Dementia of the Alzheimer Type, Multi-Infarct Dementia a nd Dementias of Other Aetiology according to ICD-10 and DSM-III-R, the Mini-Mental State Examination, the Blessed Dementia Rating Scale, the Global Deterioration Scale, the Verbal Fluency Test, the Word List Le arning Task, the Trail Making Test and the Labyrinth Test were compare d using receiver operating characteristics analysis. Results. The vali dity of composite instruments for the discrimination of dementia and c ognitive health was higher than the validity of individual tests. Howe ver, some cognitive tests, ie verbal fluency and immediate recall of w ords, reached a high validity, making them useful and short screening instruments for dementia. Conclusion. There is no perfect instrument f or screening and diagnosis of dementia. Different threshold scores for different purposes were provided in the present study. Recommendation s for improving the validity of the Delayed Word List Learning Task fo r discriminating dementia and cognitive health include the expansion o f list length and shortening of delay. (C) 1998 John Wiley & Sons, Ltd .