Funding for this research was provided by:
Ministerio de Economía, Industria y Competitividad, Gobierno de España (PSI2015-68426-R)
Eusko Jaurlaritza (Ref. IT982-16 and Ref. PI_2016_1_0023)
Received: 17 June 2019
Accepted: 19 September 2019
First Online: 20 October 2019
Compliance with Ethical Standards
: The authors declare that they have no conflict of interest.
: The study was approved by the Ethics Committee of the University of Deusto (Ref. ETK-2/14-15).
: Active consent was required from parents and adolescents to participate in the study.