1. Department of Internal Medicine, Nijigaoka Hospital , Nagasaki, Japan
2. Department of General Internal Medicine, Iwate Prefectural Isawa Hospital , Iwate, Japan
3. Department of Pharmacoepidemiology, Graduate School of Medicine and Public Health, Kyoto University , Kyoto, Japan
4. Department of Island and Community Medicine, Nagasaki University Graduate School of Biomedical Sciences , Nagasaki, Japan
5. Department of Preventive Medicine and Public Health, Keio University School of Medicine , Tokyo, Japan
6. Department of General Internal Medicine, Japan
7. Department of Clinical Epidemiology, Graduate School of Medicine, Fukushima Medical University , Fukushima , Japan