Footnotes

• Handling editor Anna Maria Geretti

• Twitter @giumas3

• Correction notice The article has been corrected since it is published. The author names have been updated.

• Contributors AL designed the work, collected the data, wrote the manuscript and revised it. MGD analysed the data and wrote the article. MG collected the data and revised the work. FM collected the data and wrote the article. MZ reviewed the letter. AC approved the final version of the 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; externally peer reviewed.