[1] Monash Univ, Monash Injury Res Inst, 21 Alliance Lane, Melbourne, Vic 3800, Australia
[2] Murdoch Childrens Res Inst, Murdoch, WA, Australia
[3] Monash Univ, Sch Psychol Sci, Melbourne, Vic 3004, Australia
[4] Childrens Hosp Philadelphia, Philadelphia, PA USA
[5] Univ Penn, Philadelphia, PA 19104 USA
[6] Univ Childrens Hosp Zurich, Dept Psychosomat & Psychiat, Zurich, Switzerland
[7] Univ Zurich, Inst Psychol, Dept Child & Adolescent Hlth Psychol, Zurich, Switzerland
[8] Univ Alberta, Dept Pediat, Edmonton, AB, Canada
[9] Univ Alberta, Dept Emergency Med, Edmonton, AB, Canada
[10] Univ Alberta, Women & Childrens Hlth Res Inst, Edmonton, AB, Canada
[11] Childrens Hosp & Clin Minnesota, Dept Pediat Emergency Med, Minneapolis, MN USA
[12] Bristol Royal Hosp Children, Emergency Dept, Bristol, Avon, England
[13] Univ W England, Fac Hlth & Appl Sci, Bristol BS16 1QY, Avon, England
[14] Meyer Univ, Childrens Hosp, Dept Emergency Med, Florence, Italy
[15] Meyer Univ, Childrens Hosp, Ctr Trauma, Florence, Italy
[16] Univ Michigan, Dept Emergency Med, Ann Arbor, MI 48109 USA
[17] Royal Childrens Hosp, Murdoch Childrens Res Inst, Melbourne, Vic, Australia
[18] Univ Melbourne, Melbourne, Vic, Australia