1. General Medicine Center, Shimane University Hospital, Shimane, Japan
2. Medicine Service, VA Ann Arbor Healthcare System, Ann Arbor, Michigan, USA
3. Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
4. Division of Medical Education, Juntendo University School of Medicine, Tokyo, Japan
5. Muribushi Okinawa Project for Teaching Hospitals, Okinawa, Japan