1. Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill
2. Department of Epidemiology, College of Public Health, University of Kentucky, Lexington, KY
3. Department of Biostatistics, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill
4. Department of Neurology, Wake Forest School of Medicine, Winston-Salem
5. East Carolina University, Brody School of Medicine, Family Medicine Center, Greenville, NC
6. Department of Physical Therapy, University of Pittsburgh, Pittsburgh, PA
7. Insight Policy Research Arlington, VA