1. School of Public Health, Lanzhou University, Lanzhou, China
2. Institute of Hospital Management, West China Hospital of Sichuan University, Chengdu, Sichuan, China
3. Saw Swee Hock School of Public Health, National University of Singapore, Singapore
4. Office of Legal Affairs, Gansu Provincial Hospital, Lanzhou, China
5. Finance Department, Gansu provincial maternity and child-care hospital, Lanzhou, China
6. Department of Radioimaging, Gansu Provincial Hospital of TCM, Lanzhou, China