1. Research Institute for Evaluation and Public Policies Universitat Internacional de Catalunya (UIC) Barcelona Catalonia Spain
2. Rhinology Unit and Smell Clinic, ENT Department Hospital Clinic, Universitat de Barcelona Barcelona Catalonia Spain
3. IRCE—Institut d'Investigacions Biomèdiques August Pi i Sunyer Barcelona Spain
4. CIBER of Respiratory Diseases (CIBERES) Instituto de Salud Carlos III Madrid Spain
5. Allergy Department Hospital Clinic Barcelona Catalonia Spain
6. RICORS—Instituto de Salud Carlos III Madrid Spain