To the Editor.—
The finding of Evans et al1 of a higher than previously reported prevalence of dementia in a sample of East Boston elders has potentially important health implications. The accompanying editorial2 raises the possibility that the high prevalence may have been linked to the low educational achievement levels of the subjects—data on which are not provided in the article. Dartigues et al3 recently reported that in a large sample of persons 65 years and older, higher education was negatively correlated with prevalence of dementia. Prevalence varied from 0.0% among subjects with a university degree or higher to more than 11.0% among subjects with no formal education. It thus seems important that future studies of the prevalence of Alzheimer's disease systematically assess achieved education and related variables and, where possible, that investigators reexamine previously reported data along these dimensions.