[1] Brigham & Womens Hosp, Div Sleep Med, Sleep Disorders Program, Boston, MA 02115 USA
[2] Harvard Univ, Sch Med, Boston, MA USA
[3] Brigham & Womens Hosp, Div Pulm Crit Care Med, Boston, MA 02115 USA
[4] Univ Hosp Cleveland, Cleveland, OH 44106 USA
[5] Case Western Reserve Univ, Cleveland, OH 44106 USA