1. Department of Family Medicine, Yonsei University College of Medicine, Seoul, Korea.
2. Department of Family Medicine, National Health Insurance Service Ilsan Hospital, Goyang, Korea.
3. Department of Family Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
4. Institute for Health Promotion & Department of Epidemiology and Health Promotion, Graduate School of Public Health, Yonsei University, Seoul, Korea.
5. Department of Family Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.