1. San Diego Veterans Affairs Healthcare System, Medicine Service La Jolla, CA
2. University of California, San Diego, Department of Medicine, San Diego, CA
3. San Francisco Coordinating Center and California Pacific Medical Center Research Institute, San Francisco, CA
4. University of California, San Diego, Department of Psychiatry, San Diego, CA
5. Brigham and Women's Hospital and Beth Israel Deaconess Medical Center, Harvard Medical School, Department of Medicine, Boston, MA
6. University of California, San Diego, Department of Family and Preventive Medicine, San Diego, CA