Cochrane review: School‐based secondary prevention programmes for preventing violence
Authors: Mytton J , DiGuiseppi C , Gough D , Taylor R , Logan S 
Published: July 2007

AbstractBackgroundEarly aggressive behaviour is a risk factor for later violence and criminal behaviour. Despite over 20 years of violence prevention interventions being delivered in the school setting, questions remain regarding the effectiveness of different interventions for children exhibiting aggressive behaviour.ObjectivesTo examine the effect of school based violence prevention programmes for children identified as aggressive or at risk of being aggressive.Search strategyWe searched CENTRAL, Cochrane Injuries Group specialised register, MEDLINE, EMBASE, other specialised databases and reference lists of articles. We also contacted authors and organisations to identify any further studies.Selection criteriaWe included trials meeting the following criteria; 1) participants were randomly assigned to intervention and control groups; 2) outcome data were collected concurrently; 3) participants comprised children in mandatory education identified as exhibiting, or at risk of, aggressive behaviour; 4) interventions designed to reduce aggression, violence, bullying, conflict or anger; 5) school based interventions; 6) outcomes included aggressive behaviour, school and agency responses to acts of aggression, or violent injuries.Data collection and analysisData were collected on design, participants, interventions, outcomes and indicators of study quality. Results of any intervention to no intervention were compared immediately post‐intervention and at 12 months using meta‐analysis where appropriate.Main resultsOf 56 trials identified, none reported data on violent injuries. Aggressive behaviour was significantly reduced in intervention groups compared to no intervention groups immediately post intervention in 34 trials with data, (Standardised Mean Difference (SMD) =‐0.41; 95% confidence interval (CI) ‐0.56 to ‐0.26). This effect was maintained in the seven studies reporting 12 month follow‐up (SMD =‐0.40, (95% CI ‐0.73 to ‐0.06)). School or agency disciplinary actions in response to aggressive behaviour were reduced in intervention groups for nine trials with data, SMD =‐0.48; 95% CI ‐1.16 to 0.19, although this difference may have been due to chance and was not maintained, based on two studies reporting follow‐up to two to four months (SMD =0.03; 95% CI ‐0.42 to 0.47). Subgroup analyses suggested that interventions designed to improve relationship or social skills may be more effective than interventions designed to teach skills of non‐response to provocative situations, but that benefits were similar when delivered to children in primary versus secondary school, and to groups of mixed sex versus boys alone.Authors' conclusionsSchool‐based secondary prevention programmes to reduce aggressive behaviour appear to produce improvements in behaviour greater than would have been expected by chance. Benefits can be achieved in both primary and secondary school age groups and in both mixed sex groups and boys‐only groups. Further research is required to establish whether such programmes reduce the incidence of violent injuries or if the benefits identified can be maintained beyond 12 months.Plain language summaryAre school‐based programmes aimed at children who are considered at risk of aggressive behaviour, effective in reducing violence?Violence is recognised as a major global public health problem, thus there has been much attention placed on interventions aimed at preventing aggressive and violent behaviour. As aggressive behaviour in childhood is considered to be a risk factor for violence and criminal behaviour in adulthood, violence prevention strategies targeted at children and adolescents, such as school‐based programmes, are considered to be promising interventions.Some school‐based prevention programmes target all children attending a school or class, whilst others confine the intervention to those children who have already been identified as exhibiting, or threatening, behaviour considered to be aggressive, such an approach is known as 'secondary prevention'. A wide variety of school‐based violence prevention programmes have been implemented over the last 20 years, yet we are still without a full understanding of their effectiveness.The objective of this systematic review was to determine the effectiveness of school‐based secondary prevention programmes to prevent violence (that is those interventions targeted at children identified as aggressive or at risk of being aggressive) .The authors examined all trials investigating the effectiveness of secondary violence prevention programmes targeted at children in mandatory education compared to no intervention or a placebo intervention.The authors found 56 studies; the overall findings show that school‐based secondary prevention programmes aimed at reducing aggressive behaviour do appear to produce improvements in behaviour. The improvements can be achieved in both primary and secondary school age groups and in both mixed sex groups and boy‐only groups.Further research is needed to investigate if the apparent beneficial programmes effects can be realised outside the experimental setting and in settings other than schools. None of the studies collected data on violent injury, so we can not be certain of the extent to which an improvement in behaviour translates to an actual injury reduction. In addition, more research is needed to determine if the beneficial effects can be maintained over time, and if the benefits can be justified against the costs of implementing such programmes.