[1] Tokyo Med & Dent Univ, Hosp Med, Trauma & Acute Crit Care Med Ctr, Bunkyo Ku, 1-5-45 Yushima, Tokyo 1138510, Japan
[2] Kameda Med Ctr, Emergency & Trauma Ctr, 929 Higashicho, Chiba, Japan
[3] Tokyo Med & Dent Univ, Grad Sch Med, Dept Hlth Policy & Informat, Bunkyo Ku, 1-5-45 Yushima, Tokyo, Japan
[4] Matsudo City Gen Hosp, Shock Trauma & Emergency Med Ctr, 933-1 Sendabori, Matsudo, Chiba, Japan