Footnotes

• MAI and HU are joint first authors.

• Contributors MAI generated the idea for the paper. MAI and HU performed the literature review and wrote the article. EP provided comments on the manuscript. MAI acts as guarantor of the content.

• 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. MAI was supported by the University of Southampton National Institute for Health Research Academic Clinical Lecturer Programme.

• Competing interests None declared.

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