1. Division of Sleep Medicine (J.J.G., K.A.S., S.B.S.K., S.M.W.R., E.V.R., J.M.Z., C.A.C., S.W.L.), Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115;
2. Faculty of Health and Medical Sciences (K.C.), University of Surrey, Guildford, Surrey GU2 7XH, United Kingdom