Footnotes

• Twitter @nicolaod_, @emilysarahdavey, @drgemmabryan

• Contributors NO’D raised the issue, conceived the letter and cowrote the letter. R-MS cowrote the letter and devised the table. ED cowrote the letter. GB cowrote the letter.

• 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.