[1] Univ Michigan, Sch Publ Hlth, Dept Biostat, Ann Arbor, MI 48109 USA
[2] Univ Michigan, Dept Neurol, Sleep Disorders Ctr, Ann Arbor, MI USA
[3] Univ Michigan, Neuropsychol Sect, Ann Arbor, MI USA
[4] Univ Michigan, Dept Psychiat, Div Child & Adolescent Psychiat, Ann Arbor, MI USA
[5] Univ Kansas, Dept Otolaryngol, Div Paediat Otolaryngol, Kansas City, KS USA
[6] Univ Penn, Childrens Hosp Philadelphia, Sch Med, Sleep Ctr, Philadelphia, PA 19104 USA