Footnotes

• Contributors All the authors provided substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data for the work; drafting the work or revising it critically for important intellectual content; final approval of the version to be published; agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

• Competing interests None declared.

• Patient consent Obtained.

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