1 Center for Clinical Epidemiology and Evidence-Based Medicine, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China.
2 Department of Nephrology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China.
3 Center for Clinical Epidemiology and Evidence-Based Medicine, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China. [email protected].