Received: 22 September 2019
Accepted: 10 January 2020
First Online: 3 February 2020
Ethics approval and consent to participate
: Participation in the study was voluntary and participants could discontinue the study at any time. All participants signed an informed consent form. Confidentiality of data was maintained; data were only discussed within the research team.The study is deemed exempt from ethical approval based on the national legislation “Bundesgesetz über die Forschung am Menschen”, Art.2, Abs.1 (ExternalRef removed), as no patient data was involved.
: Not applicable.
: The authors declare that they have no competing interests.