As the current study used retrospective publicly available data, we did not require ethics approval.

Ethics statement
In each of the participating countries, the GSHS received ethics approval from the Ministry of Education or a relevant institutional ethics review committee, or both. Only those adolescents and their parents or guardians who provided written or verbal consent participated. As the current study used retrospective publicly available data, we did not require ethics approval.

Global variation in the prevalence of bullying victimisation amongst adolescents: Role of peer and parental supports
https://www.sciencedirect.com/science/article/pii/S2589537020300201