1. Department of Emergency Medicine; Nagoya Ekisaikai Hospital; Nagoya Japan
2. Department of Public Health and Preventive Medicine; Oregon Health and Science University; Portland Oregon USA
3. Department of Emergency Medicine; Brigham and Women's Hospital; Boston Massachusetts USA
4. Department of Emergency Medicine; Ogaki Municipal Hospital; Ogaki Japan
5. Department of Healthcare Epidemiology; Kyoto University School of Medicine and Public Health; Kyoto Japan
6. Department of Emergency Medicine; Massachusetts General Hospital; Boston Massachusetts USA