[1] Univ Michigan Hlth Syst, Univ Michigan, Sch Med, Ctr Cardiovasc,Stroke Program, Ann Arbor, MI 48109 USA
[2] Univ Michigan Hlth Syst, Univ Michigan, Sch Publ Hlth, Dept Epidemiol, Ann Arbor, MI 48109 USA
[3] Univ Michigan Hlth Syst, Univ Michigan, Sleep Disorders Ctr, Ann Arbor, MI 48109 USA