1. Department of Nursing, Nanhai Hospital of Southern Medical University, Foshan, Guangdong, China.
2. General Practice Center, Nanhai 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, Ottawa, Ontario, Canada.
5. School of Epidemiology and Public Health, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada.
6. McLaughlin Centre for Population Health Risk Assessment, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada.
7. Risk Science International, Ottawa, Ontario, Canada.
8. Division of Infectious Diseases, The Ottawa Hospital, Ottawa, Ontario, Canada.
9. Department of Obstetrics and Gynecology, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada.