1. Division of Geriatrics, Duke University School of Medicine, Durham, North Carolina
2. Center for the Study of Aging and Human Development, Duke University, Durham, North Carolina
3. Duke University School of Medicine, Duke Molecular Physiology Institute, Durham, North Carolina
4. Division of Rheumatology, Duke University School of Medicine, Durham, North Carolina
5. Department of Biostatistics, Duke University School of Medicine, Durham, North Carolina
6. Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore
7. Duke Office of Clinical Research, Duke University Medical Center, Durham, North Carolina