Hajek, André http://orcid.org/0000-0002-6886-2745
König, Hans-Helmut
Article History
Received: 12 October 2018
Accepted: 30 September 2019
First Online: 15 October 2019
Ethics approval and consent to participate
: An ethical approval was not required for the study.
: Not applicable.
: The authors declare that they have no competing interests.It should be noted that one author (AH) is currently a member of editorial board (Associate Editor) of BMC Health Services Research.