Article History
Received: 17 September 2018
Accepted: 14 January 2019
First Online: 26 January 2019
Compliance with Ethical Standards
:
: K. Abraham declares that she has no conflict of interest. S. Kunst declares that there are no conflict of interest. E. Flöter declares that there are no conflict of interest.
: This article does not contain any studies with human participants or animals performed by any of the authors.
: Informed consent was obtained from all individual participants included in the study.