Affiliation: | 1. College of Medicine, School of Medicine and Health Sciences, University of Tsukuba, Tsukuba Japan ; 2. School of Medicine, Shinshu University, Matsumoto Japan ; 3. Division of General Internal Medicine, Department of Internal Medicine, Tokyo Medical University Ibaraki Medical Center, Tokyo Japan ; 4. Division of Hospital Medicine, University of Tsukuba Hospital, Tsukuba Japan |