1 Division of Pulmonary and Sleep Medicine, Bethesda North Hospital, Cincinnati, Ohio.
2 Bethanien Hospital Clinic of Pneumology and Allergology, Center for Sleep Medicine and Respiratory Care, Institute of Pneumologie at the University of Cologne, Solingen, Germany; and.
3 Division of Pulmonary, Critical Care, and Sleep Medicine, University of New Mexico School of Medicine, Albuquerque, New Mexico.