Footnotes

• Contributors MBG, CJFF and JFT planned the survey and helped launch it. MBG analysed the data. MBG and CJFF wrote the initial manuscript and the revision. All three authors approved 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.

• Patient consent for publication Not required.

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