Footnotes

• Contributors SA drafted the manuscript. RP and TJAC edited and revised the manuscript for its intellectual content. All authors contributed substantially to this manuscript and have approved the final version.

• 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 Not required.

• Provenance and peer review Commissioned; internally peer reviewed.