Received: 13 May 2019
Accepted: 3 January 2020
First Online: 2 March 2020
Ethics approval and consent to participate
: This study was approved by the Ethics Committee of the Department of Medicine of the University Hospital of the Goethe University Frankfurt am Main (Number: 518/15). All participants signed an informed consent to participate in advance, so the consent was written. Minors were excluded as participants of this study.
: Not applicable.
: The authors declare that they have no competing interests.