Footnotes

• Handling editor Anna Maria Geretti

• Contributors DR and RC designed this study. RC, DR and CF designed the survey, and RC and AS-T performed the data collection. AS-T and DR analysed the data. AS-T, RC, CF, DW and DR all contributed to the final 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.

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