Text and Data Mining valid from 2020-03-30
Received: 7 November 2019
Accepted: 11 March 2020
First Online: 30 March 2020
Ethics approval and consent to participate
: The methods and procedures of the present study were approved by the University Mayor of Santiago, Chile and were performed in accordance with the ethical standards from the 1964 Declaration of Helsinki. All participants provided approved written informed consent prior to study initiation.
: Not applicable.
: The authors declare that they have no competing interests.