Received: 19 November 2018
Accepted: 14 February 2019
First Online: 1 April 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 telephone interviews may be used for publication.
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