[Prevalence of dementia in the elderly aged above 65 in a district in the Basque Country]

To estimate the prevalence of dementia in the population aged above 65 in the district of Mungialde, Vizcaya.

We conducted a two-phase door-to-door populational study. The Minimental State Examination and the Pfeiffer questionnaire were used in the screening phase. The Clinical Dementia Rating scale, the Diagnostic and statistical manual of mental disorders and the conventional criteria employed for the different types of dementia were used in the diagnostic confirmation phase.

The first phase involved 1931 individuals and 175 cases of dementia were identified. Total prevalence was 9.1%. Prevalence was higher in females (11.8% in females versus 5.6% in males), in those over the age of 85 (34.7% versus 2% in the group with ages between 65 and 69) and in the illiterate (14.6% versus 3.4% in the group with higher education qualifications). According to the logistic regression analysis, prevalence depends on sex, age and schooling. Alzheimer's disease was the most frequent (76%) and prevalent (6.9%) dementia. It was followed by vascular dementia and dementia-Parkinson. Our study shows that the prevalence of dementia in the Basque country stands at an intermediate level in comparison to other studies carried out in our setting.

This is the first door-to-door epidemiological study conducted in the Basque Country to estimate the prevalence of dementia. It is similar to other previously reported studies. Alzheimer's disease is the most frequent form of dementia.