1. Division of General Internal Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
2. Cecil G. Sheps Center for Health Services Research, University of North Carolina, Chapel Hill, North Carolina, USA.
3. Division of Geriatrics and Palliative Care Program, Department of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA.
4. Department of Clinical Social Work, Central Regional Hospital, Butner, North Carolina, USA.
5. Department of Family Medicine, University of North Carolina, Chapel Hill, North Carolina, USA.