Footnotes

• Contributors BL had the original idea and wrote the initial draft of the manuscript. DBP had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. DS, GD, VT, JLZJ, JM and VC contributed substantially to the study design, data analysis and interpretation, and the writing of the manuscript. The data were provided through the Respiratory Effectiveness Group.

• Competing interests BL reports grants and personal fees from Chiesi, personal fees from Boerhingher Ingelheim, grants and personal fees from Meda, grants and personal fees from Teva, grants from Janssen, grants from AstraZeneca, grants from Roche, outside the submitted work; VT reports other from Cambridge Research Support, outside the submitted work; JLZJ reports other from Observational and Pragmatic Research Institute, during the conduct of the study; JM reports other from Research in Real Life, outside the submitted work; DBP has Board Membership with Aerocrine, Almirall, Amgen Inc, AstraZeneca plc, Boehringer Ingelheim, Chiesi, Meda, Mundipharma, Napp, Novartis International AG, and Teva. Consultancy: A Almirall, Amgen Inc, AstraZeneca plc, Boehringer Ingelheim, Chiesi, GlaxoSmithKline plc, Meda, Mundipharma, Napp, Novartis International AG, Pfizer, Inc. and Teva; Grants and unrestricted funding for investigator-initiated studies from UK National Health Service, British Lung Foundation, Aerocrine, AKL Ltd, Almirall, AstraZeneca plc, Boehringer Ingelheim, Chiesi, Eli Lilly, GlaxoSmithKline plc, Meda, Merck & Co., Inc, Mundipharma, Napp, Novartis International AG, Orion, Pfizer, Inc., Respiratory Effectiveness Group, Takeda, Teva, and Zentiva; Payments for lectures/speaking: Almirall, AstraZeneca plc, Boehringer Ingelheim, Chiesi, Cipla, GlaxoSmithKline plc, Kyorin, Meda, Merck & Co., Inc, Mundipharma, Novartis International AG, Pfizer, Inc., SkyePharma, Takeda, and Teva; Payment for manuscript preparation: Mundipharma and Teva; Patents (planned, pending or issued): AKL Ltd.; Payment for the development of educational materials: GlaxoSmithKline plc, Novartis International AG; Stock/Stock options: Shares in AKL Ltd which produces phytopharmaceuticals and owns 80% of Research in Real Life Ltd and its subsidiary social enterprise Optimum Patient Care; received payment for travel/accommodations/meeting expenses from Aerocrine, Boehringer Ingelheim, Mundipharma, Napp, Novartis International AG, and Teva; Funding for patient enrolment or completion of research: Almirral, Chiesi, Teva, and Zentiva; and Peer reviewer for grant committees: Medical Research Council (2014), Efficacy and Mechanism Evaluation programme (2012) and HTA (2014).

• Provenance and peer review Commissioned; internally peer reviewed.