Dementing disorders in north Italy: prevalence study in Vescovato, Cremona Province.

We investigated the prevalence of dementia in 673 subjects over 59 years of age in Vescovato, a small town of North Italy, using a two-phase survey. During phase I all subjects were administered the Hodkinson abbreviated mental test and the subjects with a score < or = 7 underwent further examination to ascertain the diagnosis of dementia. The prevalence ratio of dementia of all types was 9.8% (7.6-12.0, 95% CI) above age 59. In our population Alzheimer's disease (AD) was the most frequent type of dementia (prevalence ratio = 5.2%), followed by vascular dementia (2.7%). Our study confirms that AD prevalence estimate rises exponentially with age.