Funding for this research was provided by:
Received: 18 February 2019
Accepted: 5 August 2019
First Online: 23 August 2019
Ethics approval and consent to participate
: Not applicable; this is a post-hoc analysis using data from previously published studies. Information on ethical approval can be found in the relevant primary publications.
: Not applicable; no patient identifiable data are included in this manuscript.
: SP, DM, SL, and NB are employees of, and hold stock in GlaxoSmithKline plc. AP reports grants, personal fees, and/or reimbursement of travel expenses from AstraZeneca, Chiesi, Boehringer Ingelheim, GlaxoSmithKline plc., Menarini, Merck Sharp & Dohme, Mundipharma, Novartis, Teva, Sanofi, and Zambon.