1. Central South University Xiangya School of Nursing Changsha China
2. Johns Hopkins University School of Nursing Baltimore Maryland USA
3. Division of Geriatric Medicine and Gerontology Johns Hopkins University School of Medicine Baltimore Maryland USA
4. Drexel University College of Nursing and Health Professions Philadelphia Pennsylvania USA
5. Department of Health Policy and Management Johns Hopkins University Bloomberg School of Public Health Baltimore Maryland USA
6. Department of Epidemiology and Public Health University of Maryland School of Medicine Baltimore Maryland USA