1. Division of Pulmonary Rehabilitation, Istituti Clinici Scientifici Maugeri, IRCCS, Tradate, Italy;
2. Clinical Epidemiology of Respiratory Diseases Service, Clinical Scientific Institutes Maugeri, IRCCS, Tradate, Italy;
3. Department of Medicine and Surgery, Respiratory Diseases, University of Insubria, Tradate, Italy;
4. Allergy and Immunology Unit, Istituti Clinici Scientifici Maugeri, IRCCS, Pavia, Italy;
5. Personalized Medicine, Asthma and Allergy - Humanitas Clinical and Research Center – IRCCS, Rozzano, Italy;
6. Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Italy;
7. Clinical Epidemiology and Medical Statistics Unit, Department of Biomedical Sciences, University of Sassari, Sassari, Italy