1. Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health; University of Oxford; United Kingdom
2. Chinese Academy of Medical Sciences; Beijing China
3. Liuzhou Center for Disease Control and Prevention; Liuzhou China
4. Zhejiang Provincial Center for Disease Control and Prevention; Hangzhou China
5. China National Center for Food Safety Risk Assessment; Beijing China
6. Department of Epidemiology and Biostatistics; School of Public Health; Peking University; Beijing China