Footnotes

• Contributors The article was conceived by AZXF and AALH. AALH provided materials for the article while AZXF was responsible for the draft preparation and revision. Both authors were involved in reviewing each draft and approving the final manuscript. AALH is the guarantor of the study.

• Funding This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors.

• Competing interests None declared.

• Patient consent Next of kin consent obtained.

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