1. Health Economics Resource Center (HERC), VA Palo Alto Health Care System, Menlo Park, California, USA
2. Physical Medicine and Rehabilitation, Virginia Commonwealth University, Sheltering Arms Institute, and Central Virginia Veterans Healthcare System, Richmond, Virginia, USA
3. Department of English, College of Liberal Arts & Sciences, The University of North Carolina at Charlotte, Charlotte, North Carolina, USA
4. Department of Medicine, Division of Epidemiology, School Medicine, University of Utah, and Salt Lake City Veterans Healthcare System, Salt Lake City, Utah, USA
5. School of Medicine, University of California, San Francisco VA Healthcare System, and San Francisco VA Medical Center, San Francisco, California, USA