Received: 25 January 2020
Accepted: 24 July 2020
First Online: 3 August 2020
Ethics approval and consent to participate
: As stated in the paper: All questionnaires were completed anonymously, and ethical guidelines were strictly followed. A consent form was signed by each participant, which explained the study and the responsibilities of the participants and interviewer. All procedures performed in the study were in accordance with the ethical standards of the academic institution of the University of Freiburg and with the 1964 Helsinki declaration and its later amendments. Ethical clearing was provided for this study by the University of Freiburg (application number 153/17).
: Not applicable.
: The authors declare that they have no competing interests.