1. Department of Internal Medicine, Jeju National University School of Medicine, Jeju, Korea.
2. Department of Internal Medicine, Inje University College of Medicine, Seoul, Korea.
3. Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Korea.
4. Department of Internal Medicine, Dongguk University Gyeongju Hospital, Dongguk University College of Medicine, Gyeongju, Korea.
5. Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea.
6. Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
7. Institute for Evidence-Based Medicine, Department of Preventive Medicine, Korea University College of Medicine, Seoul, Korea.