1. Southern California Evidence-Based Practice Center, RAND Corporation, Santa Monica
2. Department of Surgery, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California3Department of Surgery, David Geffen School of Medicine, University of California, Los Angeles
3. Department of Surgery, David Geffen School of Medicine, University of California, Los Angeles
4. Department of Surgery, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California4Robert Wood Johnson Clinical Scholars Program, University of California, Los Angeles
5. Evidence-Based Synthesis Program (ESP) Center, West Los Angeles Veterans Affairs Medical Center, Los Angeles, California
6. RAND Health, RAND Corporation, Santa Monica, California