Sinusitis, Chronic

• CHU Bordeaux — Bordeaux, France
• Hôpital Henri Mondor — Créteil, France
• CHU Bicêtre, AP-HP — Le Kremlin-Bicêtre, France
• CHU Lille — Lille, France

• Tampere University Hospital — Tampere, Finland

• Department of Otorhinolaryngology, Helsinki University Hospital — Helsinki, Finland
• Kuopio University Hospital — Kuopio, Finland
• Academic Medical Center — Amsterdam, Netherlands

Not specified

• Center for Environmental Medicine, Asthma and Lung Biology — Chapel Hill, North Carolina, United States

• University of Washington — Seattle, Washington, United States

• St. Paul's Hospital — Vancouver, British Columbia, Canada