1. Advanced Medical Emergency Department and Critical Care Center Japan Red Cross Maebashi Hospital Maebashi Japan
2. Department of Emergency and Critical Care Medicine Tsukuba Memorial Hospital Tsukuba Japan
3. Department of Health Services Research University of Tsukuba Tsukuba Japan
4. Department of Emergency Medicine Kiryu Kosei General Hospital Kiryu Japan
5. Division of Traumatology Research Institute, National Defense Medical College Tokorozawa Japan