Education and other measures of socioeconomic status and risk of incident Alzheimer disease in a defined population of older persons

Objective: To assess the relations of 3 measures of socioeconomic status (education, occupational prestige, and income) to risk of incident clinically diagnosed Alzheimer disease (AD). Design: Cohort study with an average observation of 4.3 years. Setting: East Boston, Mass, a geographically defined community. Participants: A stratified random sample of 642 community residents 65 years of age and older who were free of AD at baseline. Main Outcome Measure: Clinical diagnosis of probable AD according to standard criteria, using structured uniform evaluation. Results: The relations of the 3 measures of socioeconomic status to risk of disease were assessed using logistic regression analyses. In individual analyses, fewer years of formal schooling, lower income, and lower occupational status each predicted risk of incident AD; risk of disease decreased by approximately 17% for each year of education. In an analysis including all 3 measures, the effect of education on risk for disease remained approximately the same, but the effects of the other 2 measures were somewhat less and did not attain formal statistical significance, compared with separate analysis of each measure. Conclusions: Markers of lower socioeconomic status predict risk of developing incident AD. The mechanism of this relation is uncertain, but the possibility that it reflects unidentified and potentially reversible risk factors for the disease deserves careful investigation.