1. International Centre for Reproductive Health (ICRH), Department of Public Health and Primary Care, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
2. The Research Center for Medical Sociology, Tsinghua University, Beijing, China
3. School of Public Health and Management, Wenzhou Medical University, Wenzhou, China
4. Section of Geriatrics, Department of Internal Medicine and Paediatrics, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
5. Department of Sociology, School of Social Sciences, Tsinghua University, Beijing, China
6. School of Public Health, Université libre de Bruxelles (ULB), Bruxelles, Belgium