Conflict of interest: S. Ramakrishnan declares salary support from the Charlies Foundation for Research, speaker honoraria from AstraZeneca and GlaxoSmithKline, and conference travel support from AstraZeneca. B. Montgomery declares an unpaid membership of the Guidelines Committee of the Australian Asthma Handbook, a project of the National Asthma Council Australia. I.D. Pavord has received honoraria for speaking at sponsored meetings from AstraZeneca, Aerocrine, Almirall, Sanofi/Regeneron, Menarini and GSK, payments for organising educational events from AZ, GSK and Sanofi/Regeneron, honoraria for attending advisory panels with Sanofi/Regeneron, AstraZeneca, GSK, Merck, Circassia, Chiesi and Areteia, and sponsorship to attend international scientific meetings from GSK, AstraZeneca and Sanofi/Regeneron.