Rhinosinusitis

• University Göttingen — Göttingen, Germany
• UNIVERSITÄTSMEDIZIN der Johannes Gutenberg-Universität Mainz — Mainz, Germany
• University Munich — Munich, Germany

• Sandoz Investigative Site — Burgas, Bulgaria
• Sandoz Investigative Site — Gabrovo, Bulgaria
• Sandoz Investigative Site — Plovdiv, Bulgaria
• Sandoz Investigative Site — Sliven, Bulgaria

• Central California ENT — Fresno, California, United States
• South Denver ENT and Allergy — Denver, Colorado, United States
• ENT and Allergy Associates — Trumbull, Connecticut, United States
• NorthShore University — Evanston, Illinois, United States

• Saint Joseph's Health Care — London, Ontario, Canada
• St. Joseph's Health Care — London, Ontario, Canada

• Washington University School of Medicine — St Louis, Missouri, United States

• Hospital of the University of Pennsylvania — Philadelphia, Pennsylvania, United States
• Monell Chemical Senses Center — Philadelphia, Pennsylvania, United States
• Philadelphia Veterans Affairs Medical Center — Philadelphia, Pennsylvania, United States

• Asociación Colaboración Cochrane Iberoamericana — Barcelona, Spain

• Vanderbilt University Medical Center — Nashville, Tennessee, United States

Not specified

• Fundació Institut de Recerca de l'Hospital de la Santa Creu i Sant Pau — Barcelona, Spain