biostudies-literatureBaker-Henningham HDepartment for International Development, UK GovernmentMedical Research CouncilNational Institute for Health Research (NIHR)Wellcome Truste456-e468https://www.ebi.ac.uk/biostudies/studies/S-EPMC7966677biostudies-literatureUnknown9(4)<h4>Background</h4>Violence is a leading global public health problem, and interventions in early childhood are important in the primary prevention of violence. We tested whether the Irie Classroom Toolbox, a violence-prevention teacher-training programme reduced violence against children by teachers and reduced class-wide child aggression in Jamaican preschools (catering to children aged 3-6 years).<h4>Methods</h4>We did a single-blind, cluster-randomised controlled trial in 76 preschools in Kingston and St Andrew, randomly selected, using simple randomisation, from 120 eligible preschools. Inclusion criteria were two to four classes of children; at least ten children per class; and located in an urban area. We randomly assigned preschools (1:1) to either the Irie Classroom Toolbox intervThe Lancet. Global healthThe Irie Classroom Toolbox, a universal violence-prevention teacher-training programme, in Jamaican preschools: a single-blind, cluster-randomised controlled trial.PMC7966677MR/M007553/1Baker-Henningham HWalker SPFrancis TVera-Hernandez MBowers MfalseThe Irie Classroom Toolbox, a universal violence-prevention teacher-training programme, in Jamaican preschools: a single-blind, cluster-randomised controlled trial.<h4>Background</h4>Violence is a leading global public health problem, and interventions in early childhood are important in the primary prevention of violence. We tested whether the Irie Classroom Toolbox, a violence-prevention teacher-training programme reduced violence against children by teachers and reduced class-wide child aggression in Jamaican preschools (catering to children aged 3-6 years).<h4>Methods</h4>We did a single-blind, cluster-randomised controlled trial in 76 preschools in Kingston and St Andrew, randomly selected, using simple randomisation, from 120 eligible preschools. Inclusion criteria were two to four classes of children; at least ten children per class; and located in an urban area. We randomly assigned preschools (1:1) to either the Irie Classroom Toolbox interv2021-01-01T00:00:00Z2021 Apr2025-04-20T02:26:42.191Z2025-04-20T02:26:42.191ZS-EPMC79666773363113210.1016/S2214-109X(21)00002-4