Footnotes

• Contributors JWB conceptualised and drafted the manuscript. JWB and MIB edited the manuscript and approved it for submission. JWB is responsible for the overall content as guarantor.

• 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.

• Patient consent for publication Not required.

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