Funding for this research was provided by:
Medizinischen Fakultät, Ludwig-Maximilians-Universität München (2018)
Received: 8 November 2019
Accepted: 11 December 2019
First Online: 3 January 2020
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: All procedures performed in the study were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.