Footnotes

• Contributors Submitting author is EA. Corresponding author is SI-H-O. EA and SI-H-O contributed to the conception of the work, collected data and drafted the work. SL, TB, JD, BP, LDM and ES contributed equally to the design of the work, critically reviewed the article. All authors gave final approval of the version to be published and agreed to be accountable for all aspects of the work.

• 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.