1. Department of Family Medicine, Gachon University Gil Medical Center, Incheon, South Korea
2. Department of Family Medicine, Ilsan Hospital, Goyang, South Korea
3. Department of Palliative Medicine, Seoul St. Mary’s Hospital, Catholic University College of Medicine, Seoul, South Korea
4. Department of Family Medicine, Korea University Guro Hospital, Seoul, South Korea
5. Department of Family Medicine, Catholic University St. Paul’s Hospital, Seoul, South Korea
6. Department of Family Medicine, Kyungpook National University Medical Center, Daegu, South Korea
7. Division of Hematology and Oncology, Department of Internal Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, South Korea