1. School of Public Health; Capital Medical University; Beijing China
2. Beijing Municipal Key Laboratory of Clinical Epidemiology; Beijing China
3. Evidence-based Medical Center; Xuanwu Hospital, Capital Medical University; Beijing China
4. Department of Clinical Medicine; Peking Union Medical College, Tsinghua University; Beijing China
5. National Academy of Medical Sciences, Bir Hospital; Kathmandu Nepal
6. Beijing physical examination center; Beijing China
7. Beijing Xiao-Tang-Shan Hospital; Beijing China