Ten-year incidence of dementia in a rural elderly US community population - The MoVIES Project

Objective: To determine incidence rates by age, sex, and education of overa ll dementia and probable/possible AD in a largely rural community. Methods: Ten-year prospective study of a randomly selected community sample aged 65 +; biennial cognitive screening followed by standardized clinical evaluatio n. Incidence rates were estimated for overall dementia (Diagnostic and Stat istical Manual of Mental Disorders, 3rd ed., revised, criteria and Clinical Dementia Rating [CDR]) and for probable/possible AD (National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease an d Related Disorders Association criteria). Results: The cohort consisted of 1,298 individuals free of dementia at study entry. Among these, 199 incide nt (new) cases of overall (all-cause) dementia with CDR stage greater than or equal to 0.5, including 110 with CDR greater than or equal to 1, were de tected during follow-up. Among the incident cases, 153 (76.9%) had probable / possible AD. Age-specific incidence rates are reported for all dementia a nd for probable/possible AD, by sex and CDR stage. Among all-cause dementia s with CDR = 0.5, controlling for age and education, men had a higher incid ence rate than women. In the same group, those with less than high school e ducation had significantly higher incidence rates than those with more educ ation. Rates did not vary significantly by sex or education for probable/po ssible AD or for dementia with CDR greater than or equal to 1. Conclusions: Incidence rates of all dementias and of AD increased with age; men and tho se with lesser education had higher rates of possible/incipient dementia (C DR = 0.5) in this community. Potential explanations for these sex and educa tion effects are discussed.