[1] Univ Penn, Perelman Sch Med, Dept Biostat Epidemiol & Informat, Philadelphia, PA 19104 USA
[2] Childrens Hosp Philadelphia, Violence Prevent Initiat, Philadelphia, PA 19146 USA
[3] Childrens Hosp Philadelphia, Ctr Injury Res & Prevent, Philadelphia, PA 19146 USA
[4] Columbia Univ, Coll Phys & Surg, Med Ctr, Dept Pediat, New York, NY 10027 USA
[5] Columbia Univ, Heilbrunn Dept Populat & Family Hlth, Med Ctr, New York, NY USA
[6] Mailman Sch Publ Hlth, New York, NY USA
[7] Univ Penn, Dept Publ Hlth, Philadelphia, PA 19104 USA
[8] Univ Penn, Dept Nursing, Philadelphia, PA 19104 USA
[9] Univ Penn, Dept Med, Philadelphia, PA 19104 USA
[10] Childrens Hosp Philadelphia, Div Emergency Med, Philadelphia, PA 19146 USA