1. Center for Health Promotion & Cancer Prevention, Dongnam Institute of Radiological & Medical Sciences, Busan, Korea.
2. Department of Family Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
3. JW LEE Center for Global Medicine and Department of Family Medicine, Seoul National University College of Medicine and Seoul National University Bundang Hospital, Seongnam, Korea.
4. Department of Family Medicine, National Police Hospital, Seoul, Korea.
5. Department of Family Medicine, Dong-A University College of Medicine, Busan, Korea.