1. Xiangya School of Public health, Central South University, Changsha, Hunan, China
2. Changsha Municipal Center for Disease Control and Prevention, Changsha, China
3. Sinocare Inc., No. 265 Guyuan Road Hi-tech Zone, Changsha, Hunan, China
4. Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
5. Xiangya Nursing School, Central South University, Changsha, China
6. Xiangya Hospital of Central South University, Changsha, China
7. Hunan Provincial Key Laboratory of Clinical Epidemiology, Changsha, China