1. Department of Family Medicine, Seoul National University Hospital Healthcare System Gangnam Center, Seoul, Korea
2. Department of Family Medicine, Seoul National University College of Medicine, Seoul, Korea
3. Department of Family Medicine, Daerim St. Mary’s Hospital, Seoul, Korea
4. Department of Family Medicine, H+ Yangji Hospital, Seoul, Korea
5. Department of Family Medicine, Seoul National University Boramae Medical Center, Seoul, Korea
6. Department of Family Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
7. National Cancer Control Institute, National Cancer Center, Goyang, Korea
8. Department of Family Medicine, Hallym University Sacred Heart Hospital, Anyang, Korea