[Prevalence of dementia in Gironde (France)].

The objective of the study is to estimate the prevalence of dementia using the data of the Paquid cohort. A sample of 3,149 subjects aged 65 years and older living at home or in institution was randomly chosen in Gironde (France). A questionnaire and psychometric tests were used to evaluate cognitive functioning and the presence of dementia was assessed through DSM III Diagnostic and Statistical Manual of mental disorders (ed. III) criteria. Hachinski scale and work group NINCDS-ADRDA criteria were applied to confirm the presence of dementia and identify Alzheimer's disease. Overall prevalence was estimated to 4.3%. No difference was found between men and women. The prevalence increased with age with nearly a doubling every 5 years of age. In institution, dementia frequency remained stable. The relative risk of a demented subject to be institutionalized with regard to a non demented subject decreased with age.