Funding for this research was provided by:
RWTH Aachen University
Received: 25 November 2020
Accepted: 22 February 2021
First Online: 2 March 2021
Ethics approval and consent to participate
: According to our local ethics committee (Ethics Committee at the RWTH Aachen Faculty of Medicine, chair: Günther Schmalzing), no formal ethics approval is required for this study.
: Not applicable.
: The authors declare that they have no competing interests.