Text and Data Mining valid from 2019-02-18
Received: 3 October 2018
Accepted: 18 January 2019
First Online: 18 February 2019
Compliance with ethical standards
: The authors declare that they have no competing interests.
: All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Declaration of Helsinki of 1964 and later versions.
: Informed consent or a substitute for it was obtained from all patients before they were included in the study.