Footnotes

• Twitter @edowlati

• Contributors All authors have provided substantial contributions to the conception of the work, the acquisition, analysis, drafting or revising it critically for important intellectual content; and the final approval of the version to be published. All authors agree to be accountable for all aspects of the work, including its accuracy and integrity.

• 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.

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