Funding for this research was provided by:
National Health Fund (PI15CIII/00037)
Received: 2 November 2018
Accepted: 19 June 2019
First Online: 29 June 2019
Ethics approval and consent to participate
: The authors assert that all procedures contributing to this work comply with the ethical standards of the relevant national and institutional committees on human experimentation and with the Helsinki Declaration of 1975, as revised in 2008. Oral informed consent, duly documented, was obtained from all study participants or their next of kin. The Institute of Health Carlos III Institutional Review Board approved the study and waiver of written informed consent, with a reference number CEI PI 15_2014.
: Not applicable.
: The authors declare that they have no competing interests.