1. Division of General Internal Medicine, Department of Medicine, University of Colorado School of Medicine, Aurora, CO, USA
2. Department of Family Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
3. University of Colorado School of Medicine, Aurora, CO, USA
4. Cecil G. Sheps Center for Health Services Research, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
5. Department of Health Behavior, Gillings School of Global Health, and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
6. Division of General Internal Medicine, Department of Medicine, Duke School of Medicine, Durham, NC, USA
7. Center for Health Promotion and Disease Prevention, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA