1. Department of Family Medicine, Chungbuk National University Hospital, Cheongju, Korea
2. Department of Family Medicine, Yongin Severance Hospital, Yonsei University College of Medicine, Yongin, Korea
3. Department of Family Medicine, College of Medicine, Kyung Hee University, Seoul, Korea
4. Department of Family Medicine, Korea University College of Medicine, Seoul, Korea
5. Department of Family Medicine, Hallym University Kangnam Sacred Heart Hospital, Seoul, Korea
6. Department of Family Medicine, Bundang Jesaeng Hospital, Seongnam, Korea
7. Department of Family Medicine, Haengbokhankajung Clinic, Seoul, Korea
8. Department of Family Medicine, Korea University Guro Hospital, Seoul, Korea
9. Department of Family Medicine, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea
10. Department of Family Medicine, Myongji Hospital, Goyang, Korea
11. Department of Family Medicine, SMG-SNU Boramae Medical Center, Seoul, Korea
12. Department of Family Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
13. Elderly Frailty Research Center, Department of Family Medicine, College of Medicine, Kyung Hee University, Seoul, Korea
14. Department of Internal Medicine, School of Medicine, University of Nevada, Las Vegas, USA
15. Department of Family Medicine, National Health Insurance Service Ilsan Hospital, Goyang, Korea
16. Department of Family Medicine, Chungbuk National University College of Medicine, Cheongju, Korea