Footnotes

• Contributors ACP, DM and MC conceived and planned the web-based survey. DM and MC collected all the results. VD, RB, DM and ACP contributed to the analysis and interpretation of the results. VD carried out the statistical analysis. RB and MR took the lead in writing the manuscript and DM and VD revised the manuscript critically for intellectual content. All authors provided critical feedback and helped shape the research, analysis and 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.

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