Received: 19 March 2019
Accepted: 5 December 2019
First Online: 13 December 2019
Ethics approval and consent to participate
: Participants provided verbal rather than written informed consent, due to the practicalities of carrying out a large-scale study and the low-risk nature of the survey content. Written parental or guardian consent was obtained for participants aged 15–17 years. All procedures performed in this study were approved by the University of Adelaide Human Research Ethics Committee (project H-097-2010).
: Not applicable.
: The authors declare that they have no competing interests.