Footnotes

• MM, RP and AF contributed equally to this work as first authors.

• Contributors MM, RP and AF performed data analysis and revised the manuscript critically for important intellectual content. FS, RL and VBM participated in study concept and design, and revised the manuscript critically for important intellectual content.

• Competing interests None declared.

• Ethics approval In compliance with current Italian applicable laws and regulations, considering that all data were publicly available and that the analyses included anonymised data, specific ethics approval was not required. The study was performed in accordance with the Declaration of Helsinki.

• Provenance and peer review Commissioned; externally peer reviewed.