1. Department of Family Medicine, CHA Bundang Medical Center, CHA University, Seongnam, Korea.
2. Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
3. Department of Internal Medicine, Asan Medical Center, Seoul, Korea.
4. Department of Internal Medicine, Bobath Memorial Hospital, Seongnam, Korea.
5. Department of Family Medicine, Asan Medical Center, Seoul, Korea.
6. Department of Family Medicine, Seoul National University Hospital, Seoul, Korea.
7. Department of Internal Medicine, Inje University Seoul Paik Hospital, Seoul, Korea.
8. Department of Family Medicine, Hallym University Dongtan Sacred Heart Hospital, Seoul, Korea.