1. Division of Nephrology, Department of Internal Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea;
2. Division of Nephrology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea;
3. Division of Nephrology, Department of Internal Medicine, National Health Insurance Corporation IIsan Hospital, Goyang, Korea;
4. Division of Nephrology, Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Korea;
5. Division of Nephrology, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea;
6. Division of Nephrology, Department of Internal Medicine, Yeungnam University School of Medicine, Daegu, Korea;
7. Division of Nephrology, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea;
8. Division of Nephrology, Department of Internal Medicine, College of Medicine, Chosun University, Gwangju, Korea;
9. Division of Nephrology, Department of Internal Medicine, Ulsan University Hospital, Ulsan, Korea;
10. Division of Nephrology, Department of Internal Medicine, Inje University, Haeundae Paik Hospital, Busan, Korea;
11. Division of Nephrology, Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea;
12. Division of Nephrology, Department of Internal Medicine, Chungnam National University Hospital, Daejeon, South Korea;
13. Division of Nephrology, Department of Internal Medicine, Catholic University of Daegu School of Medicine, Daegu, Korea;
14. Division of Nephrology, Department of Internal Medicine, College of Medicine, Dong-A University, Busan, Korea;
15. Division of Nephrology, Department of Nephrology, Ajou University School of Medicine, Suwon, Korea;
16. Division of Nephrology, Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea