1. Department of Preventive Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
2. School of Public Health, The Catholic University of Korea, Seoul, Korea.
3. Korea Institute of Child Care and Education, Seoul, Korea.
4. National Evidence-based Healthcare Collaborating Agency, Seoul, Korea.
5. Division of Endocrinology and Metabolism, Department of Internal Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
6. Department of Family Medicine, Seoul National University College of Medicine, Seoul, Korea.
7. Department of Family Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.