[1] Univ Penn, Penn Injury Sci Ctr, Sch Nursing, Philadelphia, PA USA
[2] Univ Penn, Leonard Davis Inst Hlth Econ, Philadelphia, PA USA
[3] Med Coll Wisconsin, Dept Emergency Med, Milwaukee, WI USA
[4] Med Coll Wisconsin, Comprehens Injury Ctr, Milwaukee, WI USA
[5] Univ Washington, Firearm Injury & Policy Res Program, Seattle, WA USA
[6] Med Coll Wisconsin, Dept Emergency Med, 8701 Watertown Plank Rd, Milwaukee, WI 53226 USA
[7] Med Coll Wisconsin, Comprehens Injury Ctr, 8701 Watertown Plank Rd, Milwaukee, WI 53226 USA