[1] Massachusetts Gen Hosp, Dept Emergency Med, 125 Nashua St,Suite 920, Boston, MA 02114 USA
[2] Natl Registry Emergency Med Technicians, Columbus, OH USA
[3] Ohio State Univ, Div Epidemiol, Coll Publ Hlth, Columbus, OH 43210 USA
[4] Ohio State Univ, Div Biostat, Coll Publ Hlth, Columbus, OH 43210 USA
[5] Ohio State Univ, Div Hlth Behav & Hlth Promot, Coll Publ Hlth, Columbus, OH 43210 USA
[6] Ohio State Univ, Dept Emergency Med, Wexner Med Ctr, Columbus, OH 43210 USA