Kalies, Helen
Schöttmer, Rieke
Simon, Steffen T
Voltz, Raymond
Crispin, Alexander
Bausewein, Claudia http://orcid.org/0000-0002-0958-3041
Article History
Received: 5 April 2017
Accepted: 21 December 2017
First Online: 5 January 2018
Compliance with ethical standards
: The study was approved by the research ethics committee of the University of Cologne (application number 14-097).
: The authors declare that they have no conflict of interest.