1. Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Korea.
2. Chung-Ang University Gwang-Myeong Hospital, Gwangmyeong-si, Korea.
3. Big Data Strategy Department, National Health Insurance Service, Wonju, Korea.
4. Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.
5. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.