1. Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, China
2. Medical Informatics Center, Peking University, Beijing, China
3. Department of Ophthalmology, Peking University People's Hospital, Beijing, China
4. Eye Disease and Optometry Institute, Peking University People's Hospital, Beijing, China
5. Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA;
6. Graduate School of Social Work, University of Denver, Denver, Colorado, USA