A web-enabled, school-based intervention for bullying prevention (LINKlusive): a cluster randomised trial

There is a need for more sustainable interventions and for assessing the effectiveness of school-based universal anti-bullying programmes in vulnerable populations. We assessed the efficacy of a multicomponent, web-enabled, school-based intervention that aims to improve school climate and reduce bullying (LINKlusive) relative to conventional practices (control condition).We conducted a cluster randomised controlled trial in primary and secondary schools in Madrid, Spain. The primary outcome measure was peer-reported bullying victimisation after the 12-week intervention (study endpoint). We analysed data using longitudinal mixed-effects models. The trial was registered with the ISRCTN registry (15719015).We included 20 schools (10 in each group); 6542 students participated at baseline; 6403 were assessed at study endpoint. After the intervention, there was a statistically significant reduction in bullying victimisation in both the intervention (OR 0.61, 95% CI [0.41, 0.90]) and control groups (OR 0.69, 95% CI [0.51, 0.92]), with no evidence of differences in the whole sample (OR 0.89, 95% CI [0.58, 1.36]; aOR 0.89, 95% CI [0.58, 1.37]). Subgroup analyses showed a statistically significant effect of LINKlusive on bullying victimisation in primary education (aOR 0.68, 95% CI [0.47, 0.98]). In students with peer-reported bullying victimisation at baseline, LINKlusive showed a statistically significant effect on depression (-1.43, 95% CI [-2.46, -0.40], adjusted standardised mean difference (SMD) -0.41) and quality of life (2.18, 95% CI [0.80, 3.56], adjusted SMD 0.45).LINKlusive could be effective in reducing bullying victimisation in primary school students. Sustainable whole-school interventions to promote mental health and reduce risk factors are warranted to improve outcomes in young people, especially in the early years of education.Instituto de Salud Carlos III, Spanish Ministry of Science and Innovation.