1. San Francisco Veterans Affairs Medical Center and University of California, San Francisco, San Francisco, California (W.R.Z., M.G.S.)
2. Wake Forest School of Medicine, Winston-Salem, North Carolina (T.E.C.)
3. University of California, San Diego, La Jolla, and Imperial Valley Family Care Medical Group, El Centro, California (R.M.)
4. University of Utah, Salt Lake City, Utah (A.K.C.)
5. University of Colorado, Aurora, Colorado (M.C.)
6. University of Minnesota, Minneapolis, Minnesota (P.D.)
7. Tufts Medical Center, Boston, Massachusetts (M.J.S.)
8. Johns Hopkins University School of Medicine, Baltimore, Maryland (C.R.P.)
9. University of California, San Diego, La Jolla, and Veterans Affairs San Diego Healthcare System, San Diego, California (J.H.I.)