Received: 6 January 2020
Accepted: 11 August 2020
First Online: 26 August 2020
Ethics approval and consent to participate
: The study was carried out in accordance with the Declaration of Helsinki. The study protocol was approved by the Dean of the University Medical Center Hamburg-Eppendorf, Hamburg, Germany since the research protocol was not deemed to be biomedical or epidemiological research. Participation in the study was voluntary. There was no disadvantage to those who chose not to participate. Participants were able to opt-out of the study without experiencing disadvantages.
: Not applicable.
: The authors declare that they have no competing interests.