1. Ubiquitous Health Center, Asan Medical Center, Seoul, Korea.
2. Department of Endocrinology/Metabolism, University of Ulsan College of Medicine, Seoul, Korea.
3. Department of Biomedical Informatics, Asan Medical Center, Seoul, Korea.
4. Medical Information Office, Asan Medical Center, Seoul, Korea.
5. Division of General Medicine and Primary Care, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts.
6. Department of Emergency Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.