Text and Data Mining valid from 2019-03-12
Received: 5 December 2018
Accepted: 23 February 2019
First Online: 12 March 2019
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: This study was in accordance with the ethical standards of our institutional review board and with the 1964 Helsinki declaration and its later amendments.
: Informed consent was obtained from all individual participants included in the study.