Text and Data Mining valid from 2018-03-19
First Online: 19 March 2018
Compliance with ethical standards
: No funding for this study.
: No conflict of interest.
: A waiver for informed consent was granted by the institutional IRB.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.