Footnotes

• Contributors MK designed and supervised the study. Data were collected and analysed by KKY. The manuscript was prepared by KKY and MK. The manuscript was critically reviewed by GC and KS without editorial support. All authors read, revised and approved the final report.

• 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 and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.

• Patient consent for publication Not required.

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