[1] Univ Iowa, Carver Coll Med, Med Scientist Training Program, Iowa City, IA USA
[2] Georgetown Univ Hosp, Washington, DC 20007 USA
[3] Washington Hosp Ctr, Dept Emergency Med, Washington, DC 20010 USA
[4] SUNY Buffalo, Dept Emergency Med, Buffalo, NY USA
[5] Univ Iowa Hosp & Clin, Dept Emergency Med, Iowa City, IA 52242 USA