1. Department of Health Policy Management, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, and Shanghai Bluecross Medical Science Institute, Shanghai, The People's Republic of China; Institute for Hospital Management, Tsing Hua University, Shenzhen Campus, The People's Republic of China
2. Gusu District Health Supervision Institute, Suzhou, Jiangsu, The People's Republic of China
3. Department of Physical Examination Center, Suzhou Industrial Park Center for Disease Control and Prevention, Suzhou, Jiangsu, The People's Republic of China
4. Department of general family medicine, Baita Community Health Service Center of Suzhou, Suzhou, Jiangsu, The People's Republic of China
5. Department of Occupational Disease, The Fifth People's Hospital of Suzhou, Suzhou, Jiangsu, The People's Republic of China.