Footnotes

• Handling editor Iskander Chaudhry.

• Correction notice This article has been corrected since it appeared Online First. The link to the digital slide has been added.

• Contributors All authors fulfil the criteria of authorship because of their substantial contribution to analysis, interpretation or manuscript preparation and have read and approved the submission of 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.

• Disclaimer The manuscript has not been published and is not being considered for publication elsewhere.

• Competing interests None declared.

• Patient consent for publication Obtained.

• Provenance and peer review Commissioned; internally peer reviewed.