[1] Univ Ferrara, Res Ctr Asthma, I-44100 Ferrara, Italy
[2] Univ Ferrara, COPD, I-44100 Ferrara, Italy
[3] Chiesi Farmaceut, Med Affairs Dept, Parma, Italy
[4] Univ Catania, Sect Resp Dis, Dept Internal & Specialist Med, Catania, Italy
[5] Univ Modena, Sect Resp Dis, I-41100 Modena, Italy
[6] Univ Parma, Dept Clin Sci, I-43100 Parma, Italy
[7] Univ Gen Hosp Verona, Pulm Unit, Verona, Italy
[8] Univ Pisa, Cardio Thorac & Vasc Dept, Pisa, Italy