[1] Univ Michigan Hlth Syst, Dept Neurol, Ann Arbor, MI USA
[2] Univ Michigan, Robert Wood Johnson Fdn, Clin Scholars Program, Ann Arbor, MI 48109 USA
[3] Ann Arbor VA Healthcare Syst, Dept Vet Affairs, VA Ctr Clin Management & Res, Ann Arbor, MI USA
[4] Univ Michigan Hlth Syst, Dept Emergency Med, Ann Arbor, MI USA
[5] Univ Michigan, Sch Publ Hlth, Dept Epidemiol, Ann Arbor, MI 48109 USA
[6] CHRISTUS Spohn Mem Hosp, Dept Emergency Med, Corpus Christ, TX USA
[7] Univ Michigan Hlth Syst, Dept Internal Med, Ann Arbor, MI USA