Footnotes

• Twitter @kaohesham

• Contributors BCHT conceived data analyses, contributed, revised, approved, supervised, and accountable for the final manuscript. LYS and VHYI collected data, contributed, approved, and accountable for the final manuscript. MFM, II, and HE contributed, approved, and accountable for the final 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.