1. Department of Clinical Epidemiology and Biostatistics; McMaster University; Hamilton; ON; Canada
2. Evidence-Based Medicine Center; School of Basic Medical Sciences; Lanzhou University; Gansu; China
3. Norwegian Knowledge Centre for the Health Services; Oslo; Norway
4. Michael G. DeGroote School of Medicine; McMaster University; Hamilton; ON; Canada
5. Influenza Division; Centers for Disease Control and Prevention; Atlanta; GA; USA
6. Iberoamerican Cochrane Centre; CIBERESP-IIB Sant Pau; Barcelona; Spain
7. Department of Pathology and Molecular Medicine; McMaster University; Hamilton; ON; Canada