1. Department of Epidemiology and Biostatistics School of Public Health, Peking University Beijing China
2. Medical Informatics Center Peking University Beijing China
3. Graduate School of Social Work University of Denver Denver Colorado USA
4. Department of Internal Medicine Yale School of Medicine New Haven Connecticut USA
5. Department of Ophthalmology Peking University People's Hospital Beijing China
6. College of Optometry Peking University Health Science Center Beijing China
7. Eye Diseases and Optometry Institute Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases Beijing China