Incidence of dementia and major subtypes in Europe: A collaborative study of population-based cohorts

The authors examined the association of incident dementia and subtypes with age, sex, and geographic area in Europe. Incidence data from eight populat ion-based studies carried out in seven European countries were compared and pooled. The pooled data included 835 mild to severe dementia cases and 42, 996 person-years of follow-up. In all studies a higher proportion of cases were diagnosed with AD (60 to 70% of all demented cases) than vascular deme ntia (VaD). The incidence of dementia and AD continued to increase with age up to age 85 years, after which rates increased in women but not men. Ther e was a large variation in VaD incidence across studies. In the pooled anal ysis, the incidence rates increased with age without any substantial differ ence between men and women. Surprisingly, higher incidence rates of dementi a and AD were found in the very old in northwest countries than in southern countries. This study confirms that AD is the most frequent dementing diso rder in all ages, and that there is a higher incidence of dementia, specifi cally AD, in women than men among the very old. Finally, there may be regio nal differences in dementia incidence.