1. From the Harvard School of Public Health, Boston, Mass (C.M., J.H.W.); Cytel Statistical Software and Services, Cambridge, Mass (C.M.); The Medicines Company, Parsippany, NJ (P.G., S.S.); Veterans Affairs Boston Healthcare System and Brigham and Women’s Hospital, Boston, Mass (D.L.B.); and Duke Clinical Research Institute, Durham, NC (R.A.H.).