1. Department of Clinical and Experimental Medicine; University of Ferrara; Ferrara; Italy
2. Respiratory Diseases; Fondazione IRCCS Policlinico San Matteo; University of Pavia; Pavia; Italy
3. Unit of Statistics and Biometry; Fondazione IRCCS Policlinico San Matteo; University of Pavia; Pavia; Italy
4. Respiratory Physio-Pathology Unit; Hospital-University of Ferrara; Ferrara; Italy
5. Department of Oncology; Haematology and Respiratory Diseases; University of Modena & Reggio Emilia; Modena; Italy