1. Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, England
2. Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, England2Medical Research Council Population Health Research Unit, University of Oxford, Oxford, England
3. Chinese Academy of Medical Sciences, Beijing, China
4. Qingdao Center for Disease Control and Prevention, Qingdao, China
5. Henan Provincial Center for Disease Control and Prevention, Henan, China
6. National Center for Food Safety Risk Assessment, Beijing, China
7. Chinese Academy of Medical Sciences, Beijing, China7School of Public Health, Peking University, Beijing, China