25 July 2016

Mentoring systematic review is published

New systematic review published on mediation, mentoring and peer support to reduce youth violence. 

This systematic review is the second to be published by the What Works Centre for Crime Reduction from a series of 12.  Forthcoming reviews cover a wide-range of topics from domestic abuse to speed cameras and use of tagging in shops to reduce theft.  All of our new systematic reviews report on the effectiveness of interventions in the Crime Reduction Toolkit - including how it works, where it works, how to do it and its cost.

This systematic review has been carried out by the London School of Hygiene and Tropical Medicine as part of the Commissioned Partnership Programme.

Systematic Reviews are used to help make sense of the vast amount of research relating to the effectiveness of crime reduction interventions such as mentoring, mediation and peer support.  Using the findings from individual studies may be misleading because they may use different measures of success and may be based on a variety of research methodologies, some of which may be too weak to be able to draw conclusions. A systematic review aims to minimise bias by setting standards for methodology that studies must meet before they are included in the review and being clear about the outcomes.  For this series of studies a reduction in crime must be the measured outcome in the study for the research to be included in the review.

What is did the systematic review cover?

This review included programmes which contained one or more components of mediation, mentoring, or peer support.  For each intervention or programme the participant characteristics, setting, recruitment methods, theoretical basis used in the design of the intervention components, intervention aims, characteristics (i.e., components, content, mode, and delivery), processes and outcomes were described.


Systematic reviews use inclusion criteria to identify eligible studies and this review included interventions that involved contact and interaction with a positive role model. The role model might be a peer (of similar age and/or background), a mentor (someone with more experience, skills and abilities), or a peer mediator who intervenes between youth to prevent retaliation. To control for the methodology used by relevant studies only certain research designs were included in the review, including randomised controlled trials (RCT), cluster randomised trials (CRT), controlled before-after (CBA) studies, cohort studies and case-control (CC) studies.


As the focus of the review was on reducing youth violence, participants of interventions had to be perpetrators of violence and those at risk of violence who were aged less than 25 years. In order for studies to be included in the review the measurable outcome had to be carrying a weapon, violence, offending, and health service use due to injury. Crime and self-reported outcomes were included.


What did the Systematic Review find?

Most of the interventions included mentoring, mediation or peer-support as only one component of many in a broader package of services for youth violence prevention. It was therefore not possible to attribute any effects to a single component of the programme.  This highlights the difficulty of researching programmes which include a number of different interventions as researchers cannot be sure which components have caused the effect.


The systematic review reported that the methodological quality of future evaluations of mentoring, mediation or peer-led interventions to prevent youth violence needs to be improved in order to gain better insight into what works in reducing youth violence.


What did the systematic review tell us about the impact of mediation, mentoring and peer support on reducing crime?

Mentoring – this involves interaction between two individuals over an extended period of time and is based on encouraging healthy development of mentees, providing them with direct and indirect support, and potentially reducing the time they can engage in criminal activities. Overall, the evidence suggests mentoring reduced reoffending but there is also some evidence to the contrary.  Go to the Crime Reduction Toolkit for a fuller explanation of the impact of mentoring on crime reduction.

Mediation - evidence from two studies on mediation provided little evidence of effect on reducing violent behaviour, carrying weapons, arrests and reconvictions.

Peer-led interventions - evidence from five studies on peer-led interventions found weak evidence for effect on reducing aggressive behaviour and attitudes conducive to violent behaviour, and no evidence for effect on weapon-enabled violence, arrests and reconvictions.

You can download the full systematic review and access additional information by visiting the Mentoring page of our What Works: Crime Reduction Systematic Review Series.

For more information about the What Works Centre, email whatworks@college.pnn.police.uk

 What Works: Crime reduction systematic review series