Polytechnic University of Marche - Department of Biomedical Sciences and Public Health, Respiratory Diseases Unit, Azienda Ospedaliero-Universitaria “Ospedali Riuniti”, Polytechnic University of Marche - Centre of Epidemiology, Biostatistics and Information Technology, 1Department of Biomedical Sciences and Public Health, Marche Polytechnic University, Respiratory Diseases Unit, “Ospedali Marche Nord”, Department of Cardio-Thoracic-Vascular Sciences and Public Health, University of Padova, Respiratory Diseases Unit, “Guido Salvini” Hospital, Air Pollution Project, Health Department “Regione Marche”, Respiratory Diseases Unit, “San Giuseppe”, Respiratory Diseases Unit, “Ospedali Marche Nord”, Polytechnic University of Marche - Department of Experimental and Clinical Medicine, Respiratory Diseases Unit, Azienda Ospedaliero-Universitaria “Ospedali Riuniti”, Emergency Unit, Azienda Ospedaliero-Universitaria “Ospedali Riuniti”, IRCCS - Ospedale San Giuseppe MultiMedica - U.O. di Pneumologia, Respiratory Diseases Unit, “Spedali Civili” Hospital, Department of Cardio-Thoracic-Vascular Sciences and Public Health, University of Padova, Emergency Unit, Azienda Ospedaliero-Universitaria “Ospedali Riuniti”, Respiratory Diseases Unit, “Spedali Civili” Hospital, GB Morgagni Hospital - Radiology Department, GB Morgagni Hospital - Pulmonary Unit, Respiratory Diseases Unit, Dept of Diseases of the Thorax, Ospedale GB Morgagni, Department of Cardio-Thoracic-Vascular Sciences and Public Health, University of Padova, Liver diseases and Transplant Unit, Azienda Ospedaliero-Universitaria “Ospedali Riuniti”, Careggi University Hospital - Department of Clinical and Experimental Medicine, Respiratory Diseases Unit “Santa Maria degli Angeli” Hospital, Pneumology Service, Azienda Sanitaria dell’Alto Adige, Respiratory Diseases Unit “Santa Maria degli Angeli” Hospital, Pulmonary Disease Unit, Department of Internal Medicine, Azienda Ospedali Riuniti, Department of Biomedical Sciences and Public Health, Università Politecnica delle Marche, Pulmonary Disease Unit, Department of Internal Medicine, Azienda Ospedali Riuniti, Department of Biomedical Sciences and Public Health, Università Politecnica delle Marche and Marche Polytechnic University - Centre of Epidemiology and Biostatistics

University of Milan - Respiratory Unit, Department of Health Sciences, Università degli Studi di Milano, Respiratory Unit, ASST Santi Paolo e Carlo, San Paolo Hospital, Department of Health Sciences, Università degli Studi di Milano, School of Medicine and Surgery, University of Milano Bicocca, Respiratory Unit, San Gerardo Hospital, ASST Monza, School of Medicine and Surgery, University of Milano Bicocca, Respiratory Unit, San Gerardo Hospital, ASST Monza, School of Medicine and Surgery, University of Milano Bicocca, Respiratory Unit, San Gerardo Hospital, ASST Monza, University of Milano-Bicocca - S. Gerardo Hospital - Respiratory Unit, ASST Lodi, UOC Medicina Interna, SST Lodi, UOC Pneumologia, ASST Lodi, UOC Pneumologia, Respiratory Unit, Papa Giovanni XXIII Hospital, Department of Health Sciences, Università degli Studi di Milano, Respiratory Unit, Papa Giovanni XXIII Hospital, Papa Giovanni XXIII Hospital, Respiratory DiseasesUnit, Fondazione IRCCS Policlinico San Matteo, Respiratory Diseases Unit, Fondazione IRCCS Policlinico San Matteo, Respiratory Diseases Unit, Fondazione IRCCS Policlinico San Matteo,Department of Internal Medicine and Therapeutics, University of Pavia, Pulmonary Disease Unit, Department of Internal Medicine, Azienda Ospedali Riuniti, Department of Biomedical Sciences and Public Health, Università Politecnica delle Marche, Polytechnic University of Marche - Department of Biomedical Sciences and Public Health, Pulmonary Disease Unit, Department of Internal Medicine, Azienda Ospedali Riuniti, Department of Biomedical Sciences and Public Health, Università Politecnica delle Marche, linical Epidemiology and Medical Statistics Unit, Dept of Medical, Surgical and Experimental Medicine, University of Sassari, Department of Health Sciences, Università degli Studi di Milano, Respiratory Unit, ASST Santi Paolo e Carlo, San Paolo Hospital, Department of Health Sciences, Università degli Studi di Milano, Respiratory Unit, ASST Santi Paolo e Carlo, San Paolo Hospital, Department of Health Sciences, Università degli Studi di Milano, Respiratory Unit, ASST Santi Paolo e Carlo, San Paolo Hospital, Department of Health Sciences, Università degli Studi di Milano and Clinical Epidemiology and Medical Statistics Unit, Dept of Medical, Surgical and Experimental Medicine, University of Sassari