Text and Data Mining valid from 2020-03-06
Received: 24 April 2019
Accepted: 14 February 2020
First Online: 6 March 2020
Ethics approval and consent to participate
: The research project was approved by the Comité de Ética de la Investigación (CEIC) del Hospital Universitario Ramón y Cajal. All subjects give voluntary written informed consent to participate in research.
: Not applicable.
: The authors declare that they have no competing interests.