1. Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, NC, USA
2. University of North Carolina School of Medicine, Chapel Hill, NC, USA
3. Department of Surgery, University of North Carolina School of Medicine, Chapel Hill, NC, USA
4. Kenan-Flagler Business School, University of North Carolina, Chapel Hill, NC, USA
5. Department of Family Medicine, University of North Carolina School of Medicine, Chapel Hill, NC, USA