1. Institute of Hospital Administration, Xiangya Hospital, Central South University, Changsha, Hunan, China;
2. Department of Scientific Research, Xiangya Hospital, Central South University, Changsha, Hunan, China;
3. Department of Nephrology, Xiangya Hospital, Central South University, Changsha, Hunan, China;
4. Department of Science and Education, The First People’s Hospital of Changde City, Changde, Hunan, China;
5. Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario, Canada;
6. Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada