Footnotes

• Handling editor Runjan Chetty.

• Contributors RM conceived the study. AC and RM wrote the manuscript. AL-B, MS and LC provided expert revision. All authors reviewed and contributed to the manuscript.

• 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.