Funding for this research was provided by:
Medical University of Vienna
Received: 26 June 2019
Accepted: 16 October 2019
First Online: 28 November 2019
Compliance with ethical standards
: The methods mentioned in this study were in accordance with the ethical standards of the institutional research committee and with the principles of the 1964 Declaration of Helsinki and its later amendments.
: The authors declare that they have no conflict of interest.