Text and Data Mining valid from 2018-03-12
Received: 18 November 2017
Revised: 22 February 2018
Accepted: 23 February 2018
First Online: 12 March 2018
Compliance with ethical standards
: On behalf of all authors, the corresponding author states that there is no conflict of interest.
: 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.
: Informed consent was obtained from all participants included in the study prior to accessing the survey.