Received: 25 July 2019
Accepted: 8 November 2019
First Online: 28 November 2019
Ethics approval and consent to participate
: Ethical approval was obtained from the ethics committee of the University of Bremen (Germany) on 10.05.2016. The involved patients and researchers gave written informed consent.
: The involved patients and researchers gave written consent that the results from the qualitative investigation may be used for publication.
: The authors declare that they have no competing interests.