Text and Data Mining valid from 2019-02-20
Received: 9 October 2018
Accepted: 30 January 2019
First Online: 20 February 2019
Compliance with ethical standards
: The authors declare that they have no conflicts of interest.
: Informed consent was obtained from all individual participants included in the study. The study was reviewed and approved by our local ethical committee.
: 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.