1. Department of Nursing The Seventh Affiliated Hospital of Southern Medical University Foshan Guangdong China
2. Digestive Medical Center The Seventh Affiliated Hospital of Southern Medical University Foshan Guangdong China
3. Division of Respirology Department of Medicine, The Ottawa Hospital Ottawa Ontario Canada
4. Ottawa Hospital Research Institute Clinical Epidemiology Program Ottawa Ontario Canada
5. School of Epidemiology and Public Health, Faculty of Medicine University of Ottawa Ottawa Ontario Canada
6. McLaughlin Centre for Population Health Risk Assessment, Faculty of Medicine University of Ottawa Ottawa Ontario Canada
7. Risk Science International Ottawa Ontario Canada
8. Department of Obstetrics & Gynecology University of Ottawa Faculty of Medicine Ottawa Ontario Canada