Evaluation of Liaison and Diversion services in England

British judge with gavel and justice scales

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Our evaluation of NHS England's Liaison and Diversion programme found that it successfully engages people with a broad range of vulnerabilities and halves their likelihood of receiving a custodial sentence.

What is the issue?

Liaison and diversion (L&D) schemes aim to improve the early identification of people with a range of vulnerabilities — such as mental health issues and learning disabilities — who come into contact with the youth or adult criminal justice system (CJS). Once their needs are identified, individuals can be referred to appropriate interventions or treatment in the healthcare system.

NHS England launched national, 24-hour, seven-day-a-week, L&D services in 2014. The aim of the programme was to improve health and social care outcomes for individuals, and decision making within the CJS, by providing timely and accurate information about health needs and vulnerabilities.

How did we help?

Following our study into the early implementation of the national model for L&D, we were commissioned by NHS England to evaluate the impact of the L&D scheme in 27 sites in England.

To do so, we created a large-scale linked data set combining information from four separate healthcare sources and two separate criminal justice sources. We looked at:

  • health service utilisation      

  • reconviction

  • diversion from the criminal justice system

  • timeliness of court processes, and

  • the economic effects of any identified impacts on the outcomes above.

To our knowledge this is the first example of such an extensive, cross-sector data linkage study. It enabled us to evaluate L&D services using data from 8,729 service users referred to L&D services between January and September 2017. These service users consented to the use of their data, and researchers followed up with them for at least 12 months. We also used the linked data to create an historic control group.

What did we find?

  • L&D services successfully engaged people with a broad range of vulnerabilities. Overall, 88 per cent of people referred to L&D services had at least one vulnerability identified.
  • L&D services appear to intervene at a point of crisis, often when people are most in need of support. We identified increased use of multiple healthcare services in the months leading up to the arrest that led to referral to an L&D service.
  • The likelihood of service users receiving a custodial sentence is halved following involvement with L&D services. The L&D scheme may reduce the proportion of offences resulting in custodial sentences and thus increase diversion from the criminal justice system.
  • There was substantial variation between L&D services in the types of interventions offered, and referrals to healthcare services often did not translate into face-to-face contact with health service providers.
  • Referral to mental health services may increase, but these referrals do not appear to lead to an increase in attendances.
  • Drug and alcohol treatment referral and attendance may increase.
  • Referral to L&D services does not appear to reduce offending.
  • Court processes are not significantly affected by L&D services. The duration of court proceedings was reduced for offences committed but there is not enough evidence to conclusively demonstrate an impact on this outcome.
  • There was no evidence that outcomes became worse due to L&D referral, and we did not identify any unintended consequences of referral.
  • The L&D programme contributes to savings in the criminal justice system, but not in the healthcare system. L&D services appear to directly contribute savings of between £13.1 million and £41.5 million in the criminal justice system through diversion from custody and consequent increases in productivity.

What could be done?

Some factors of the programme that could be addressed to improve the overall impact of L&D services include increasing capacity for onward referrals and developing approaches to support people who have multiple vulnerabilities but are not currently eligible for referral because no single vulnerability meets a required therapeutic threshold.