METHODS
Study Population
Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) is a population-based cohort study involving 3720 participants that is supported by the Intramural Research Program of the National Institute on Aging.26 Study participants, who were 30 to 64 years of age and living in Baltimore at the time of enrollment, were recruited from 13 contiguous U.S. Census tracts. Participants were randomly selected within strata based on age, race, sex, and socioeconomic status; those who did not identify themselves as black or white were excluded. The institutional review board of the National Institute of Environmental Health Sciences, National Institutes of Health, approved the protocol. The Partners HealthCare Human Research Committee exempted the present study from the requirement for review. The first and last authors vouch for the accuracy of the data and analyses.