Funding for this research was provided by:
Medical Research Council (G1001367/1)
Received: 9 September 2020
Accepted: 14 April 2021
First Online: 20 April 2021
Ethics approval and consent to participate
: Ethical approval was granted from the Hamstead research ethics committee (Ref. 09/H0720/8) and all patients gave written informed consent.
: Not applicable.
: RS—Reports grants from GSK, Teva and personal fees from Boehringer Ingelheim outside the submitted work. KBRB—Reports grants from Alpha-1 foundation outside the submitted work. PF—The author declares that they have no competing interests. KKC—The author declares that they have no competing interests. GD—Reports grants from Aztra Zeneca and personal fees from Astra-Zeneca, American Thoracic Society and FWO Flanders outside the submitted work. JW—Reports grants from GSK, Novartis, Boehringer Ingelheim, Astra Zeneca and Chiesi outside the submitted work. PJB—Reports grants and personal fees from Astra Zeneca, Boehringer Ingelheim, and personal fees from Novartis, Pieris and Epi-Endo outside the submitted work. LED—Reports grant from Astra-Zeneca and Boehringer Ingelheim outside the submitted work.