1. Department of Epidemiology and Health Statistics, West China School of Public Health and West China Fourth Hospital Sichuan University Chengdu Sichuan China
2. Department of Environmental Health and Occupational Medicine, West China School of Public Health and West China Fourth Hospital Sichuan University Chengdu Sichuan China
3. Department of Osteoporosis, West China School of Public Health and West China Fourth Hospital Sichuan University Chengdu Sichuan China