1. Division of General Internal Medicine, Department of Medicine, University of California, San Francisco, USA
2. Department of Urology, University of California, San Francisco, USA
3. San Francisco VA Medical Center, California, USA
4. Research Institute, California Pacific Medical Center, San Francisco, USA
5. Department of Epidemiology and Biostatistics, University of California, San Francisco, USA
6. Oregon Health and Science University-Portland State University School of Public Health, USA
7. Division of Geriatrics, Department of Medicine, University of California, San Francisco, USA
8. Department of Orthopaedics and Rehabilitation, Oregon Health and Science University, Portland, USA