1. From the School of Public Health (E.B.C.) and the Department of Neurosurgery, School of Medicine (E.B.C., R.G.W.V.), Yale University, New Haven, CT; the Department of Neurosurgery, Brigham and Women’s Hospital, Boston (E.B.C.); and the Department of Neurosurgery, Amsterdam University Medical Center, Amsterdam (R.G.W.V.).