Italian Longitudinal Study on Ageing: incidence study of dementia

The Italian Longitudinal Study on Ageing (ILSA) is a population-based, multicentre study focusing on normal ageing and ageing pathology. Prevalence, incidence and risk factors for specific age-associated diseases, such as dementias will be investigated. A sample of 5,056 subjects 64 + resident in the field areas will be selected. The incidence rates will be estimated by using two subsequent prevalence surveys. In the first prevalence survey, each sampled subject will undergo the Mini-Mental-State examination as screening. Those who have been screened positive, will undergo an extensive diagnostic workup to identify dementia cases and to classify them as Alzheimer's disease, vascular dementia or other dementias, according to the DSM-IIIR, ICD-10R and NINCDS-ADRDA criteria. Subjects identified as non-cases will be re-assessed 3 years later by using the same procedure, instruments and criteria to estimate incident cases. Finally, genetic and environmental risk factors for Alzheimer's disease and vascular dementia will be assessed by means of case-control studies, one on prevalent and one on incident cases, and of the cohort study. The project started in January 1991.