1. Department of Family Medicine, Wonkwang University Sanbon Hospital, Wonkwang University School of Medicine, Gunpo, Republic of Korea.
2. International Healthcare Center, Asan Medical Center, Seoul, Republic of Korea.
3. Department of Family Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
4. Department of Family Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
5. Department of Family Medicine, Bundang Jesaeng General Hospital, Seongnam, Republic of Korea.
6. Department of Family Medicine, Yeungnam University Medical Center, Yeungnam University College of Medicine, Daegu, Republic of Korea.