Footnotes

• SFJ and CJR contributed equally.

• Contributors CJR and SFJ both contributed to conceptualising and drafting the manuscript. Each approved the final version 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.