Table 1.

Inclusion and exclusion criteria.

Inclusion Criteria	Exclusion Criteria
English language	Articles not in English
Peer-reviewed articles	Books, conference presentations, PhD theses/dissertations, PowerPoint presentations and posters, government reports
The article reports on an empirical study, systematic review, or review/commentary/discussion article addressing the topic	Study protocols
Published 1 January 2015–26 August 2020	Published prior to 2015
The focus of the article is on gambling, and addresses adolescent and/or youth (10–25 years) * attitudes and/or behaviours towards gambling	The article does not address adolescent and/or youth attitudes and/or behaviours towards gambling, or does not include young people and older adults, but reported only aggregated data
Studies of any quality according to quality appraisal	Only reported on prevalence/incidence

* Articles that included older adults but reported adolescent or young people’s data separately are included.