May 9, 1990

The Presence of Alzheimer's Disease in a Community Population

Author Affiliations

Mayo Foundation Rochester, Minn

Mayo Foundation Rochester, Minn

JAMA. 1990;263(18):2447-2448. doi:10.1001/jama.1990.03440180045020

To the Editor.—  The importance and several limitations of the study by Evans et al1 on Alzheimer's disease in the East Boston population were recognized in the accompanying editorial by Dr Larson.2 We wish to congratulate the authors for providing additional age-specific prevalence rates for the dementias. Elucidation of geographic and population patterns of dementia is necessary to develop hypotheses related to the pathophysiology of common dementing illnesses such as Alzheimer's disease. Increasing support by the National Institute on Aging for epidemiologic studies—including those at various centers in the United States and the studies being undertaken in the Mariana Islands, which will use mainland rates as a basis for comparison—is timely and appropriate.As Evans et al point out, the difficulties of case ascertainment and uniformity of diagnosis in the ongoing studies require that they "be interpreted with caution." In the East Boston study, the diagnosis of dementia