[1] King Saud Univ, Prince Sultan Bin Abdelaziz Coll Emergency Med Ser, Dept Accid & Trauma, Riyadh, Saudi Arabia
[2] Univ Manchester, Div Cardiovasc Sci, Manchester, England
[3] King Saud Bin Abdulaziz Univ Hlth Sci, Coll Appl Med Sci, Riyadh, Saudi Arabia
[4] North West Ambulance Serv NHS Trust, Med Directorate, Bolton, England
[5] Univ Sheffield, Sch Hlth & Related Res, Sheffield, England