Conflict of interest: M. Dransfield reports grants or contracts from the American Lung Association, the US Department of Defense and the US National Institutes of Health, consulting fees from AstraZeneca, GlaxoSmithKline, Novartis, Pulmonx and Teva, and support for attending meetings from Pulmonx. R. Kalhan reports grants from the National Heart, Lung, and Blood Institute, the Respiratory Health Association, PneumRx, Spiration and AstraZeneca, and personal fees from AstraZeneca, CVS Caremark, GlaxoSmithKline, CSA Medical and Boehringer Ingelheim. D. Stolz reports a grant from the Swiss National Foundation (SNF 320030_189280), and unrestricted grants from Curetis, AstraZeneca and Boston Scientifics (paid to their institution); honoraria for participation in data safety monitoring or advisory boards, or lectures from CSL Behring, Berlin-Chemie Menarini, Novartis, GlaxoSmithKline, AstraZeneca, Vifor, Merck, Sanofi, Merck Sharp & Dohme, Boehringer Ingelheim and Chiesi; and is the current Global Initiative for Chronic Obstructive Lung Disease (GOLD) representative for Switzerland, the immediate past Education Council Chair of the European Respiratory Society, and President of the Education Committee of the Swiss Respiratory Society.