Footnotes

• Contributors JVZ and MV contributed equally to this manuscript. They conceived the protocol, retrieved patient data and wrote and edited the manuscript. JVZ is responsible for the overall content as the guarantor. DM performed the statistical analysis. RM, KB and KVB treated the patients. KVB edited 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; externally peer reviewed.