[1] Christiana Care Hlth Syst, Dept Emergency Med, Newark, DE 19713 USA
[2] Brigham & Womens Hosp, Dept Emergency Med, Boston, MA 02115 USA
[3] Univ Penn, Dept Emergency Med, Perelman Sch Med, Philadelphia, PA 19104 USA
[4] Univ Virginia Univ Hosp, Dept Emergency Med, Charlottesville, VA USA
[5] Beth Israel Deaconess Med Ctr, Dept Emergency Med, Boston, MA 02215 USA
[6] Beth Israel Deaconess Med Ctr, Dept Internal Med, Boston, MA 02215 USA