1. Department of Family Medicine, China Medical University, Taichung, Taiwan, Republic of China;
2. Department of Public Health, National Defense Medical Center, Nei-Hu, Taipei, Taiwan, Republic of China;
3. Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Kaohsiung, Taiwan, Republic of China;
4. Department of Family Medicine and Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Nei-Hu, Taipei, Taiwan, Republic of China;
5. Institute of Occupational Safety and Health, Council of Labor Affairs, Shi-Jr, Taipei, Taiwan, Republic of China;
6. Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Nei-Hu, Taipei, Taiwan, Republic of China