1. Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry, and Pharmaceutical Sciences Okayama University Okayama Kita‐ku Okayama Japan
2. Department of Emergency and Critical Care Medicine St. Luke's International Hospital Chuo‐ku Tokyo Japan
3. Department of Emergency, Disaster and Critical Care Medicine Hyogo Emergency Medical Center Chuo‐ku Kobe Japan
4. Department of Emergency Medicine Teikyo University School of Medicine Itabashi‐Ku Tokyo Japan
5. Department of Emergency, Disaster, and Critical Care Medicine Kagawa University Hospital Miki‐cho, Kita‐gun Kagawa Japan
6. Department of Epidemiology, Faculty of Medicine, Dentistry, and Pharmaceutical Sciences Okayama University Okayama Kita‐ku Okayama Japan