1. Department of Medicine, Division of General Internal Medicine, Duke University, Durham, NC, USA
2. Department of Clinical Research, Duke University Medical Center, Durham, NC, USA
3. Department of Community and Family Medicine, Division of Community Health, Duke University, Durham, NC, USA
4. Center for Health Services Research in Primary Care, Durham, VA Medical Center, Durham, NC, USA
5. Department of Medicine, Division of General Internal Medicine, Palliative Care Section, Center for the Study of Aging and Human Development, Duke University, Durham, NC, USA