1. Carolina Population Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
2. Department of Social Medicine, University of North Carolina School of Medicine, Chapel Hill, NC, USA
3. Harris School of Public Policy, University of Chicago, Chicago, IL, USA
4. School of Medicine, Duke University, Durham, NC, USA
5. Robert N. Butler Columbia Aging Center and Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY, USA
6. Department of Sociology, Duke University, Durham, NC, USA
7. School of Social Work, University of North Carolina at Chapel Hill, NC, USA
8. Department of Sociology, University of North Carolina, Chapel Hill, NC, USA