1. Harvard Graduate School of Arts and Sciences, Cambridge; and Harvard Business School, Boston, Massachusetts (M.T.)
2. Department of Health Care Policy, Harvard Medical School, Boston, Massachusetts (C.H.N.)
3. Harvard Business School, Boston; and Harvard-MIT Center for Regulatory Science, Boston, Massachusetts (A.D.S.)
4. Department of Health Care Policy, Harvard Medical School, Boston; Department of Biostatistics, Harvard School of Public Health, Boston; and Department of Statistics, Harvard University, Cambridge, Massachusetts (J.R.Z.)
5. Division of General Internal Medicine, Massachusetts General Hospital, Boston, Massachusetts (F.O.M.)
6. RAND Corporation, Arlington, Virginia (L.U.)
7. Stroke Division, Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts (L.H.S.)
8. Department of Health Care Policy, Harvard Medical School, Boston; and Beth Israel Deaconess Medical Center, Boston, Massachusetts (A.M.).