1 Respiratory Rehabilitation of the Institute of Tradate, Istituti Clinici Scientifici Maugeri, IRCCS, Tradate, Italy. Electronic address: elisabetta.zampogna@icsmaugeri.it.
3 Respiratory Rehabilitation of the Institute of Tradate, Istituti Clinici Scientifici Maugeri, IRCCS, Tradate, Italy.
4 Department of Medicine and Surgery, Respiratory Diseases, University of Insubria, Varese-Como, Italy.
5 Allergy and Immunology Unit, Istituti Clinici Scientifici Maugeri, IRCCS, Pavia, Italy.
6 Clinical Epidemiology and Medical Statistics Unit, Department of Medical, Surgical and Experimental Sciences, University of Sassari, Sassari, Italy.
7 Respiratory Rehabilitation of the Institute of Tradate, Istituti Clinici Scientifici Maugeri, IRCCS, Tradate, Italy; Department of Medicine and Surgery, Respiratory Diseases, University of Insubria, Varese-Como, Italy.