Footnotes

• Contributors All authors, JT, KVH and FC, compiled the response to the letter by Rey, Sanders and Aziz. All authors, JT, KVH and FC, contributed to drafting and finalising the letter. JT submitted the letter.

• 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.