Footnotes

• Twitter @FragoulisGeorge

• Contributors GEF and GE: study design, data analysis and interpretation, drafting the manuscript. AA, V-KB, KF, AK, EK, KL, SP, MP: data acquisition. MGT: study design, data analysis and interpretation. PPS: study inception and design, data analysis and interpretation. All authors critically revised and approved the final version of 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 GEF: has received speaker honoraria from Janssen, travelling grants from AbbVie and MSD. MGT: has received consultant fees and unrestricted grants from AbbVie, MSD, Novartis, Pfizer, GSK and UCB deposited to the Special Account for Research Funding (ELKE) of the National and Kapodistrian University of Athens Medical School. PPS: has received consultant fees and unrestricted grants from AbbVie, Pfizer, MSD, Roche, UCB, GSK and Novartis deposited to the Special Account for Research Funding (ELKE) of the National and Kapodistrian University of Athens Medical School.

• 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.

• Ethics approval This study was conducted according to the Declaration of Helsinki and was approved by the Scientific Council of the 'Laiko' hospital (No: 2020/14/4).

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