Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou, Guangdong 510080,China;
Department of Medical Information, School of Medicine, Jinan University, Guangzhou, Guangdong 510632, China;
Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou, Guangdong 510080,China;