1 Department of Otorhinolaryngology, Academic Medical Centre, Amsterdam, The Netherlands.
2 European Forum for Research and Education in allergy and Airway Diseases (EUFOREA), Brussels, Belgium.
3 Ghent University Hospital, Ghent, Belgium.
4 Karolinska Institute, Stockholm, Sweden.
5 INSERM U 1168, VIMA: Ageing and Chronic Diseases Epidemiological and Public Health Approaches, Villejuif, Université Versailles St-Quentin-en-Yvelines, UMR-S 1168, Montigny le Bretonneux, France.
6 MACVIA-France and fondation FMC-VIA-LR, Montpellier, France.
7 Department of Respiratory Medicine, Ghent University Hospital, Gent, Belgium.
8 Department of Pneumology, CHU Liege, GIGA I3, University of Liege, Liege, Belgium.
9 Department of Pulmonology, Cliniques Universitaires St-Luc and Research Pole of Pneumology, ENT and Dermatology, Université Catholique de Louvain, Brussels, Belgium.
10 Department of Otorhinolaryngology, Head and Neck Surgery, Medical Faculty Mannheim, Universitätsmedizin Mannheim, Heidelberg University, Mannheim, Germany.
11 Center for Rhinology and Allergology, Wiesbaden, Germany.
12 Centre of Academic Primary Care, University of Aberdeen, Aberdeen, UK.
13 Observational and Pragmatic Research Institute, Singapore, Singapore.
14 Department of Otorhinolaryngology, University of Crete School of Medicine, Heraklion, Greece.
15 The Royal National Throat Nose & Ear Hospital, London, UK.
16 Medtronic ENT, Tolochenaz, Switzerland.
17 Chordate Medical, Kista, Sweden.
18 Clinical Division of Otorhinolaryngology, Head and Neck Surgery, University Hospitals Leuven, Leuven, Belgium.