1. VA Nebraska‐Western Iowa Health Care System Omaha NE USA
2. University of Nebraska Medical Center Omaha NE USA
3. Pittsburgh VA & University of Pittsburgh Pittsburgh PA USA
4. Corporal Michael J. Crescenz VA Medical Center and University of Pennsylvania Philadelphia PA USA
5. VA Puget Sound Health Care System and University of Washington Seattle WA USA
6. Boston VA Boston MA USA
7. Dallas VA & University of Texas Southwestern Dallas TX USA
8. Washington D.C. VA, Howard University, & Georgetown University Washington D.C. USA
9. VA Salt Lake City Health Care System and University of Utah Salt Lake City UT USA