Footnotes

• Contributors CH and PAL conceived of the article. DC provided guidance on content. CH and PAL wrote the first draft. All authors contributed to the final draft and approved it for publication.

• 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 and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.

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