Footnotes

• Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

• Competing interests Speaker’s and consulting fees from AstraZeneca, Bayer and Sanofi-Aventis.

• Patient consent Not required.

• Provenance and peer review Commissioned; externally peer reviewed.

• Author note References that include an asterisk (*) are considered to be key references.