1. Department of Emergency, Critical Care, and Disaster Medicine, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
2. Department of Epidemiology, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
3. Department of Emergency Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA.
4. Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA.
5. Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA.