1. School of Public Health, Shanxi Medical University, Taiyuan, China
2. School of Management, Shanxi Medical University, Taiyuan, China
3. Clinical Laboratory, Jiaozhou Central Hospital of Qingdao, Qingdao, China
4. Department of Neonatal Intensive Care Unit, Qingdao Women and Children’s Hospital, Qingdao, China
5. School of Public Policy and Administration, Xi’an Jiaotong University, Xi’an, China
6. Affiliated Shenzhen Maternity and Child Healthcare Hospital, Southern Medical University, Shenzhen, China.