1. Shenzhen Qianhai Shekou Free Trade Zone Hospital, Shenzhen 518067, China
2. Department of Public Health and Preventive Medicine, School of Medicine, Jinan University, Guangzhou 510632, China
3. Department of Neonatology and Pediatrics, The First Affiliated Hospital, Jinan University, Guangzhou 510630, China
4. Baoan Center for Chronic Diseases Control, Shenzhen 518101, China