Footnotes

• Contributors DMGH wrote the first draft and then JKQ and DMGH both contributed to subsequent drafts.

• Funding None.

• Competing interests DMGH has received sponsorship to attend international meetings and honoraria for lecturing, attending advisory boards and preparing educational materials from Almirall, AstraZeneca, Boehringer Ingelheim, Chiesi, GSK, Intermune, MSD, Nycomed and Pfizer. His department has received research funding from AstraZeneca. JKQ is funded on an MRC Population Health Scientist Fellowship. She has also received research funding from GSK, the BLF, has received sponsorship to attend international meetings and honoraria for lecturing and preparing educational materials from Almirall, AstraZeneca and GSK.

• Provenance and peer review Not commissioned; internally peer reviewed.