1. Department of Epidemiology and Biostatistics, Drexel University School of Public Health, Philadelphia, PA, USA
2. Epidemiology and Biostatistics, Shandong University School of Public Health, Jinan, Shandong, China
3. National Center for Chronic and Noncommunicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
4. Bureau of Epidemiology, Pennsylvania Department of Health, Harrisburg, PA, USA
5. Department of Epidemiology, The Fourth Military Medical University School of Public Health, Xi'an, Shaanxi, China