1. Department of Primary Care and Medical Education, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Japan
2. Department of Medicine, Mito Kyodo General Hospital, University of Tsukuba, Japan
3. Department of General Medicine, Juntendo University School of Medicine, Japan
4. Department of Emergency and Critical Care Medicine, Mito Kyodo General Hospital, University of Tsukuba, Japan
5. Center for Global Health, Mito Kyodo General Hospital, University of Tsukuba, Japan