Footnotes

• Collaborators Dr. Gennadiy Voronov.

• Contributors IAS designed and conducted the study including data collection and analysis. IAS elaborated the manuscript draft with important inputs from KT and NR-M who revised it critically for intellectual content. All authors approved the final manuscript and had full access to the study data.

• 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; externally peer reviewed.