Received: 2 November 2017
Accepted: 29 March 2018
First Online: 22 May 2018
Ethics approval and consent to participate
: The project was registered and approved by the Ethics Board of the University of Freiburg (AN-EK-FRBRG-582/16). Furthermore, the project was approved according to the Act on Processing of Personal Data (journal no. 16/28232) and by the Danish Patient Safety Authority (journal no. 3-3013-1811/1/).
: The authors declare that they have no competing interests.
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