Footnotes

• Twitter @MattTaberner, @nathspencer, @jarrodantflick, @danielcohen1971

• Contributors MT designed the infographic. MT wrote the initial draft of the accompanying text which was modified and a final version agreed between MT, NS, BM, JA and DDC.

• 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 None declared.

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