1. Department of Internal Medicine; Niigata University Faculty of Medicine; Niigata Japan
2. Health Management Center; Toranomon Hospital; Tokyo Japan
3. Okinaka Memorial Institute for Medical Research; Tokyo Japan
4. Centre for Medical Sciences; Ibaraki Prefectural University of Health Sciences; Ibaraki Japan
5. Department of Pharmacoepidemiology; Graduate School of Medicine and Public Health; Kyoto University; Kyoto Japan
6. Department of Internal Medicine; University of Tsukuba Institute of Clinical Medicine; Ibaraki Japan