1. Division of Colorectal Surgery, Taipei Medical University Hospital, Taipei, Taiwan
2. Department of Surgery, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwa
3. Department of Surgery, Changi General Hospital, Singapore, Singapore
4. Biostatistics and Research Consultation Center, Taipei Medical University, Taipei, Taiwan
5. Tangyueher occupational clinic, Taipei, Taiwan