Received: 27 May 2019
Accepted: 14 January 2020
First Online: 23 January 2020
Ethics approval and consent to participate
: Data for this analysis were approved by the University Biomedical Ethics board (17–399) and the northern health regions, and written permission from the superintendents of the school boards and the principals of the five participating high schools was received. Written parental consent and student assent were obtained from each participant aged ≤17. Adolescents aged ≥18 were granted permission by the ethics board and school districts to provide their own written consent.
: Not Applicable.
: The authors declare no competing interests.