1. Stanford–Surgery Policy Improvement Research and Education Center (S-SPIRE), Department of Surgery, Stanford University School of Medicine, Palo Alto, California, USA.
2. Department of Surgery, Stanford University School of Medicine, Palo Alto, California, USA.
3. Division of General Surgery, Palo Alto Veterans Affairs Health Care System, Palo Alto, California, USA.
4. Department of Emergency Medicine, Stanford University School of Medicine, Palo Alto, California, USA.
5. Division of Endocrinology, Gerontology and Metabolism, Stanford University School of Medicine, Palo Alto, California, USA.
6. Geriatric Research, Education and Clinical Center, Veterans Affairs Palo Alto, Palo Alto, California, USA.
7. Division of Nephrology, Stanford University School of Medicine, Palo Alto, California, USA.