1. Department of Family Medicine, School of Medicine, Kyungpook National University, Daegu, Korea
2. Department of Family Medicine, Kyungpook National University Hospital, Daegu, Korea
3. Department of Family Medicine, Uijeongbu Eulji Medical Center, Eulji University School of Medicine, Uijeongbu, Korea
4. Department of Family Medicine, Korea University College of Medicine, Seoul, Korea
5. Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea