[1] Univ Michigan, Dept Emergency Med, Ann Arbor, MI 48109 USA
[2] Univ Michigan, Inst Healthcare Policy & Innovat, Acute Care Res Unit, Ann Arbor, MI 48109 USA
[3] RAND Corp, Santa Monica, CA USA
[4] Univ Michigan, Dept Family Med, Ann Arbor, MI 48109 USA
[5] Vet Affairs Hlth Syst, Ctr Clin Management Res, Ann Arbor, MI USA
[6] Alpena Cty EMS, City Alpena Fire Dept, Alpena, MI USA
[7] St Joseph Mercy Hlth Syst, Dept Emergency Med, Ann Arbor, MI USA
[8] Univ Michigan Hlth Syst, Dept Emergency Med, Ann Arbor, MI 48109 USA
[9] Univ Michigan Hlth Syst, Div Cardiovasc Dis, Ann Arbor, MI USA