Footnotes

• Contributors SK designed the study, developed the first draft of the questionnaire, analysed results and wrote the first draft of the manuscript. SW helped with every revision of the questionnaire, disseminated the survey and contributed to writing the manuscript. LS helped draft the questionnaire, analysed results and contributed to writing the manuscript. SL helped draft the questionnaire and contributed to writing the manuscript. PDG helped draft the questionnaire and contributed to writing the manuscript. MS helped design the study, drafted the questionnaire and wrote the first draft of the manuscript.

• Competing interests None declared.

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