Conflict of interest: A.G. Mathioudakis reports grants from Boehringer Ingelheim, outside the submitted work. Conflict of interest: P. Sivapalan reports personal fees for lectures from Boehringer Ingelheim, outside the submitted work. Conflict of interest: A. Papi reports grants, personal fees for advisory board work, consultancy and lectures, and travel expenses reimbursement from GlaxoSmithKline, AstraZeneca, Boehringer Ingelheim, Chiesi Farmaceutici and TEVA, personal fees for advisory board work, consultancy and lectures, and travel expenses reimbursement from Mundipharma, Zambon, Novartis and Sanofi/Regeneron, grants, personal fees for lectures, and travel expenses reimbursement Menarini, personal fees for advisory board work and consultancy, and travel expenses reimbursement from Roche, grants from Fondazione Maugeri and Fondazione Chiesi, personal fees for consultancy from Edmondpharma, outside the submitted work. Conflict of interest: J. Vestbo reports personal fees for advisory board work and lectures from AstraZeneca, grants and personal fees for lectures from Boehringer Ingelheim, personal fees for advisory board work and lectures from Chiesi and Novartis, personal fees for advisory board work from GSK, outside the submitted work; and has a family member who is employed by Chiesi.