Funding for this research was provided by:
Bundesministerium für Bildung und Forschung
Ministry of Culture and Science of the State of North Rhine-Westphalia
German Federal Ministry of Health
Received: 27 November 2020
Accepted: 25 February 2021
First Online: 4 May 2021
: The study was performed according to the Declaration of Helsinki, approved by the ethics committee of the Medical Faculty of Heinrich Heine University Düsseldorf. All participants gave written informed consent before inclusion in the study.
: All authors have seen and approved the manuscript being submitted.
: The authors declare no competing interests.