1. Department of Medicine, Center for Research on Health Care Data Center, University of Pittsburgh, PA (A.D.A.).
2. Heart and Vascular Institute at the University of Pittsburgh Medical Center, PA (S.K.J., M.S., S.S.).
3. Cardiology Division, Department of Medicine at the VA Pittsburgh Healthcare, PA (A.S.).
4. Cardiology Division, Ohio State University, Columbus (R.W.).
5. Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque (L.M.).
6. Cardiology Division, Duke University Medical Center, Durham, NC (S.M.A.-K.).