1. Division of Gastroenterology, Taipei City Hospital Yang-Ming Branch, Taipei, Taiwan
2. Department of Internal Medicine, Taipei City Hospital Yang-Ming Branch, Taipei, Taiwan
3. School of Medicine, National Yang-Ming University, Taipei, Taiwan
4. Department of Education and Research, Taipei City Hospital, Taipei, Taiwan
5. Institute of Public Health and Department of Public Health, National Yang-Ming University, Taipei, Taiwan