Program effectiveness varies by country: Greece led for perpetration, Italy for victimization¶

Claim · All claims
Evidence · 1 study (2 entries) · quant-synthesis r2–r3 · q4
Currency · newest study 2019 · checked against its sources 2026-10-20 (automated, 2 of 2 entries) · not reviewed by a person

Subclaims¶

q4 i? Among countries with multiple evaluations, Greece was most effective for perpetration, followed by Norway, Italy, the USA, and Finland. → Hannah Gaffney 2019 q4 i? Among countries with multiple evaluations, Italy was most effective for victimization, followed by Spain, Norway, the USA, and Finland. → Hannah Gaffney 2019 (2)

Evidence¶

Hannah Gaffney 2019¶

Hannah Gaffney, David P. Farrington, & Maria M. Ttofi. (2019). Examining the Effectiveness of School-Bullying Intervention Programs Globally: a Meta-analysis. International Journal of Bullying Prevention. https://doi.org/10.1007/s42380-019-0007-4

q4 · i? · quant-synthesis · r3

Country-level moderator analysis of weighted mean odds ratios across 22 countries (Table 2), restricted to "international locations where more than one evaluation was conducted."

"evaluations carried out in Greece were the most effective in significantly reducing bullying perpetration, followed by Norway, Italy, the USA, and Finland."

Hannah Gaffney 2019 (2)¶

Hannah Gaffney, David P. Farrington, & Maria M. Ttofi. (2019). Examining the Effectiveness of School-Bullying Intervention Programs Globally: a Meta-analysis. International Journal of Bullying Prevention. https://doi.org/10.1007/s42380-019-0007-4

q4 · i? · quant-synthesis · r2

Country-level moderator analysis for victimization across 21 countries (Table 2); the authors add that evaluations in Germany and the UK were also significantly effective.

"evaluations conducted in Italy were the most effective in significantly reducing bullying victimization, followed by Spain, Norway, the USA, and Finland."

Discussion¶

Related Claims¶

• The Olweus Bullying Prevention Program produced the largest effect sizes for bullying perpetration, with effectiveness varying between Norway and USA evaluations — related
• Regional differences in program effectiveness: North America led for perpetration, Scandinavia for victimization, with no clear overall pattern — related
• Effectiveness of anti-bullying programs varies significantly across evaluations (heterogeneity) — a broader claim this one bears on
• School-based anti-bullying programs reduce bullying perpetration and victimization globally — a broader claim this one bears on
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• The bullying-achievement and mediation associations are moderated by design, assessment method, country, age and bullying type
• School-based anti-bullying programs decrease victimization by 17-20% on average — related
• School-based anti-bullying programs are effective overall, decreasing bullying by 20-23% on average — related
• Anti-bullying intervention effects are weak, and RCT designs show even smaller effects than earlier meta-analyses suggested — related