SYNOPSIS

In February 2020, there were over 83,000 people incarcerated in England and Wales, the majority (95%) of whom were male. The rate of mental illness in this group is very high and much higher than the general population1,2 (Table 1). Prevalence rates vary internationally due to methodological differences, but a consistent finding is that about one in seven people in prison have major depression or psychosis.1 Comorbidity for this group is the norm, as are chaotic lifestyles with a wide range of personal and social problems, including homelessness, unemployment and broken relationships with partners and children.9 In our earlier descriptive study,10 we found that of 200 offenders (100 offenders serving prison sentences and 100 offenders serving community sentences), 59% reported having common mental health problems, 37% reported problems with family relationships and the majority (65–70%) were unemployed or on long-term sickness benefit. For people leaving prison, the transition into the community is associated with increased rates of suicide and self-harm. For example, the risk of suicide for male offenders leaving prison is eight times the national average.11,12 Although mental illness rates for female prisoners are consistently higher,13 the Engager project focused on male prison leavers because of the smaller numbers of females in prison estates.

In 2018, 63% of custodial sentences received were for less than 12 months.14 Short custodial sentences are known to be less effective than community sentences at reducing reoffending,15 with the 12-month proven reoffending rates for short-sentence prisoners currently close to 60%.16 As well as reoffending, frequent transitions in and out of prison take a high toll on the individual, their family and their social tenure.17 Comorbidity is high for this group,18 as is the financial cost of failing to address these health and social care issues.19

In the UK, although the NHS commissions all health services, it appoints a range of providers from NHS, private, and voluntary and community sectors. On the one hand, a prison may have multiple providers and each service will provide a specific service only (e.g. primary care, general physical health care, mental health care). On the other hand, in some cases, a prison may use a number of different providers for services such as primary and secondary mental health care, or drug and alcohol services. However, using a number of different providers can make continuity of care more complex, especially for people who require input from multiple services, as often these providers do not operate in an integrated way. This issue is further complicated at the point of release, as often the health-care providers within a prison will not be the same services that operate in the community.

There has been investment in prison mental health services for those with severe and enduring mental illness.20 There is research evidence that critical time intervention, that is, a structured, time-limited form of case management,21 can be adapted for people with severe and enduring mental illness who are in prison. In a randomised controlled trial (RCT),22 critical time intervention demonstrated increased engagement with community mental health services at 6 weeks post release from prison.

The identification of common mental health problems may occur during induction, through self-reporting or when staff raise concerns. However, we know from other studies that this will miss many people and will under-represent the level of need.23 In addition, provision of psychological therapy for people with common mental health problems who are in contact with the criminal justice system (CJS) is limited in both prison and community settings.10 Once released into the community, ex-prisoners with common mental health problems are, in theory, provided for by mainstream statutory services, including general practice, community mental health teams and Improving Access to Psychological Therapies (IAPT) services; however, few ex-prisoners access these services,10 suggesting that a lack of care on release is the norm.24

Despite negligible uptake and high need, to the best of our knowledge, worldwide, no systems have been identified for actively engaging people with common mental health problems while in prison, providing support and working with them to engage with community services. Organisational interventions, such as collaborative care (i.e. a complex intervention based on a chronic disease management model), have been shown to be beneficial for those with depression25 and comorbid physical health problems.26 However, such interventions are yet to be tested with prison leavers. Elements of collaborative care have the potential to ensure continuity over time and co-ordination between teams and practitioners, as well as support for self-care.

The points above provide clear theoretical grounds for the potential health gain in developing an intervention that (1) focuses on short-term prisoners with common mental health problems, (2) takes a collaborative care approach to span all the different agencies/professionals involved and (3) takes into account the wide range of social and health problems individuals may face. There is very limited research into developing and evaluating mental health interventions within prisons.27 RCTs within the CJS can be more complex than in other settings because of a range of factors, such as organisational difficulties, maintaining trial arm allocation, poor follow-up rates and difficulties selecting appropriate outcome measures.1,17,28–30

How to navigate the Engager research programme and report

The National Institute for Health and Care Research-funded Engager research programme ran between 2013 and 2020, across two phases. Figure 1 depicts the whole Engager research programme. The Engager research programme was designed to work iteratively between questions relating to intervention development and questions relating to trial science. The Engager research programme included four interlinked workstreams delivered across two phases. Workstream 4, addressing health economics, continued across both phases.

FIGURE 1 The Engager research programme. (Figure not reproduced here; see the original article.)

Phase 1: intervention development and trial methodology

A mixed-methods approach was used for the development of a theoretically informed person-centred co-ordinated intervention (workstream 1) and this involved:

• a realist review
• organisational case studies
• focus groups
• a rapid realist review of implementation
• a formative process evaluation.

The data were brought together at two time points (i.e. synthesis 1 and synthesis 2) to iteratively develop the theory and practice of the intervention. The Engager intervention is summarised in this synopsis, with more detail provided in Report Supplementary Material 6.

In parallel, we developed the trial science methodology to evaluate the intervention (workstream 2) and this involved:

• selection of outcome measures
• development of tools to measure ‘the process of care’
• a pilot trial to test the trial procedures
• initial health economics modelling (workstream 3).

Phase 2: trial, process evaluation and cost-effectiveness (workstreams 3 and 4)

In phase 2 we conducted:

• an RCT
• a cost-effectiveness analysis and a cost–consequence analysis
• a mixed-methods process evaluation, which took a realist-informed approach to examining fidelity, problems with implementation and potential improvements to theory.

Our patient and public involvement work was extensive and interwoven through all workstreams and both phases. For ease of reading, workstream 4 has been split into two sections, that is, phase 1 (economic modelling) and phase 2 (cost-effectiveness and cost–consequence analyses).

Alterations to the programme

The initial contract was to develop the intervention and to carry out an exploratory trial. A proposal to switch to a definitive trial was agreed at the mid-programme checkpoint report. An extension to collect data at 12 months was agreed once recruitment viability had been established in the main trial. Owing to the decision to have a definitive trial, along with issues of data availability, it was agreed that the initial plan for decision modelling of economic benefits of a full trial would be replaced by carrying out a trial-based cost–consequence analysis.