Funding for this research was provided by:
Instituto de Salud Carlos III (RD07/0063)
Received: 11 February 2019
Accepted: 20 December 2019
First Online: 6 January 2020
Ethics approval and consent to participate
: All participants provided written informed consent before entering the study, which adhered to the tenets of the Declaration of Helsinki. The Institutional Review Board of the University of Navarra approved the study.
: Not applicable.
: The authors declare that they have no competing interests.