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24/29 The health of children and young people in contact with the criminal justice system


Published: 19 March 2024

Version: 1.0 March 2024

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Research Question

  • What interventions have an impact on the physical or mental health of children and young people in contact with the criminal justice system?

Children and young people (hereafter referred to simply as ‘children’) who come into contact with the criminal justice system (CJS) are one of the most marginalised and vulnerable population subgroups in the UK. There is no singular risk factor associated with offending behaviour in children, and no factors exist in isolation. Rather, risk factors interact, can be cumulative, and children in contact with the CJS are often subject to multiple and varied system failures and negative experiences – some of them traumatic. There is substantial evidence to show that children in contact with the CJS have poorer health outcomes than those in the general population (translating over time into shorter life expectancy), often due to multiple and complex unmet physical and mental health needs. Likewise, these children often tend to have poorer educational attainment than children in the general population. This call for research focuses on children who have come into contact with the CJS at any stage. The scope of this call includes, for example, children supervised by youth justice services or in contact with police services, as well as those in custody. The Public Health Research (PHR) programme recognises that the UK has three distinct criminal justice systems: England and Wales, Scotland, and Northern Ireland, and is interested in the evaluation of interventions from across the UK.

In England and Wales in 2021-22, approximately 13,800 children (10 to 17 years old) received a caution or sentence, with an average of 450 children in custody at any one time. Rates of children entering the youth justice system for the first time have decreased significantly in the last decade. Nevertheless, there is a trend towards longer sentencing of older children, and these children are likely to face transition into adult estates in the CJS. Most children who receive a caution or sentence in England are male (86% in 2021-22). Children from ethnic minority backgrounds are over-represented in the CJS. There is also an over-representation of children entering the justice system who are neurodivergent (who have, for example, attention deficit hyperactivity disorder (ADHD), autism spectrum disorders, or a history of traumatic brain injury).

Coming into contact with the CJS can increase health inequalities as a result of reduced opportunities for physical activity, restricted or negative social interactions, and access to worthwhile activities, that in turn could impact negatively on physical and mental health. Simultaneously, there are also opportunities within the CJS to deliver interventions which could have both an acute and lasting impact on health outcomes. Opportunities for delivery may occur at various points in the system, for example from initial contact with the police, at court diversion or sentencing, whilst serving a sentence, and through to post-release. Some aspects of the structured youth justice environment can be viewed as an opportunity for education provision, seeking to reduce health risks from – for example – smoking, alcohol, and substance misuse. There may also be opportunities to deliver interventions such as those aiming to increase vaccination and screening uptake. Evidence suggests that programmes such as those centred around sports and the arts, can be an effective part of diversionary and rehabilitative approaches. Data are relatively sparse on interventions in youth justice settings that are effective at improving the physical and mental health outcomes of children. Moreover, it is not clear whether or to what extent positive changes in health behaviours are maintained

Preventing children from offending and coming into contact with the CJS is a key consideration in avoiding escalating levels of harm to both children and wider society. In addressing the issue, it is essential to tackle the wider health and social determinants of offending and reoffending behaviours, typically through a collaborative and multi-sectoral approach – which includes services related to health (physical and mental), education, social care, law enforcement, and others.

The PHR Programme wishes to commission research on the effectiveness of interventions that impact the physical and mental health of children in contact with the CJS. The PHR Programme is predominantly interested in interventions operating at a population/group level rather than at an individual level, which should address health inequalities and the wider determinants of health. The PHR Programme recognises that interventions are likely to impact different (sub)populations in different ways and encourages researchers to explore such inequalities of impact in their study design.

Suggested areas of research could include, but are not limited to, evaluation of:

  • Interventions that address the multiple, interacting disadvantages that affect the most marginalised children in contact with the CJS, including trauma-informed interventions
  • Interventions, including whole system approaches, aimed at preventing children from repeatedly coming into contact with the CJS (i.e. targeting those who have already been in contact with the CJS) for example as a result of a second or subsequent offence
  • Interventions that include improved data linkage and/or multi-agency data sharing
  • Interventions that enhance levels of education and training (and/or employment where appropriate) for children in contact with the CJS
  • Interventions that focus on mental ill-health (including interventions aimed at reducing self-harm) or that focus on substance and alcohol misuse, among children in contact with the CJS
  • Interventions addressing the needs of children who may be neurodivergent or who have a learning disability, and who are in contact with the CJS
  • Interventions for children who may be at risk of offending/re-offending, including health economic models
  • Interventions that focus on the physical health of children in contact with the CJS, including for example in relation to dental health, sexual health, smoking cessation, and uptake of screening (where relevant) and vaccinations
  • Interventions addressing access (increased access and equity of access) to physical activity and/or sport for children in contact with the CJS
  • Interventions that support young people’s transition into adulthood in the context of the CJS, including those transitioning into adult probation services
  • Interventions which aim to teach or develop independent living and general life skills to children in contact with the CJS
  • Peer or family support interventions aimed at improving health outcomes, such as interventions looking to build social capital or re-establish support networks for children in contact with the CJS
  • Interventions seeking to provide continuity of care for children spanning criminal justice settings and post-release.

A range of study designs and outcome measures can be used. Researchers will need to clearly describe and justify their target population and outcomes, as well as the rationale for their methodological approach. The PHR Programme typically requires primary outcomes to be direct health outcomes. However, given the focus of this commissioned call, the Programme will accept proxy measures for health – for example rates of education, training or employment for young adults – as long as the link to health is clearly justified. Researchers are encouraged to consider additional outcome measures including those relating to the wider determinants of health and health inequalities, which should be specified and justified. Researchers will also need to specify key outcomes and how these will be measured in the short, medium and long term. It is recognised that health outcomes of interest may only be reached later in a person’s lifecourse.

Understanding the value of public health interventions – whether outcomes justify their use of resources – is integral to the PHR Programme, where resources relating to different economic sectors and budgets are potentially relevant. The main outcomes for economic evaluation are expected to include health (including health-related quality of life) and the impact on health inequalities as a minimum, with consideration of broader outcomes welcomed. Different approaches to economic evaluation are encouraged as long as they assess the value and distributive impact of interventions. Applications that do not include an economic component should provide appropriate justification.

Researchers are strongly encouraged to ensure that service users, including children with lived experience from the target population and their carers, if appropriate, are meaningfully involved in the design and planning of the intervention and/or as potential, suitably rewarded, members of the research team. Researchers should demonstrate the relevance of their proposed research to decision-makers and people with lived experiences and they might do this through involving them as costed/rewarded members of the research team. Researchers are encouraged to explain how they will share their findings with policy makers, public health officers, special interest groups, charities, community audiences and other relevant stakeholders. Researchers are expected to be aware of other studies in this area, development in practice and ensure their proposed research is complementary.

The Youth Endowment Fund (YEF) will consider co-funding projects with NIHR where applicants are interested in evaluating interventions that will benefit children who are at risk of becoming involved in violence or who are already involved in violence. Where NIHR agree to fund research costs, YEF may part or fully fund intervention costs. YEF is primarily looking for interventions that will impact one of our primary outcomes (please see the Outcomes Framework) and meet all criteria set out in the eligibility checker. Applicants meeting these criteria can contact the YEF grants team directly to discuss further on

For further information on submitting an application to the PHR Programme, please refer to the supporting information for applicants submitting stage 1 and stage 2 applications.