1. School of Medicine University of California, San Francisco San Francisco California USA
2. Division of Geriatrics, Department of Medicine University of California, San Francisco San Francisco California USA
3. Department of Epidemiology & Biostatistics University of California, San Francisco San Francisco California USA
4. Division of Geriatrics, Department of Medicine San Francisco Veterans Affairs Health Care System San Francisco California USA
5. Department of Orthopaedic Surgery University of California, San Francisco San Francisco California USA
6. Department of Epidemiology Boston University Boston Massachusetts USA
7. Department of Anesthesia & Perioperative Care University of California, San Francisco San Francisco California USA