1. Division of Surgical Oncology, Department of Surgery Duke University Durham North Carolina USA
2. Department of Biostatistics and Bioinformatics Duke University Durham North Carolina USA
3. Department of Surgery Durham VA Health Care System Durham North Carolina USA
4. Geriatrics Research Education and Clinical and Clinical Center Durham Virginia USA
5. Department of General Surgery Stanford University School of Medicine Stanford California USA
6. Division of Geriatrics, Department of Medicine, Center for the Study of Aging and Human Development, Center for Palliative Care Duke University School of Medicine Durham North Carolina USA