The effectiveness of interventions
Last week (24 April 2025), the MoJ published a reducing reoffending evidence synthesis which provides an overview of evidence on what works to reduce reoffending, updating evidence previously published by the MOJ in 2013 and 2014. The report focuses upon the evidence base for some of the key areas of MOJ policymaking, but it is clearly not exhaustive. It revisits some of the same areas as previous reviews, including more recent evidence and incorporating new areas such as debt and community ties.
Evidence is drawn primarily from a series of Rapid Evidence Assessments (REAs) conducted by academics working in the field of reducing reoffending. REAs were used to compile sections on: Accommodation, Education, Employment, Finance, Benefits and Debt, and Community Ties. The REAs focused upon the effectiveness of these types of interventions to reduce reoffending but included some additional follow up questions such as features of effective interventions of different types, and for whom they may be most effective.
A REA was also commissioned on theories of desistance. For the remaining sections, MOJ analysts conducted internal reviews of recent evidence, prioritising meta-analyses and focusing on UK evidence but including some international studies.
Findings
The strength of the evidence base for different types of intervention varies considerably. For each type, the report also indicates the scale of the reduction of reoffending. The synthesis found a good research base for the following types of intervention:
- Supervision by (trained) probation staff
- Accommodation (if delivered alongside support)
- Education
- Drug misuse programmes
- Cognitive behavioural programmes
- Restorative justice
The review found mixed/promising evidence for employment and mentoring interventions and insufficient evidence for interventions addressing alcohol; finance, benefit & debt; community ties and mental health needs. It’s important to clarify that the evidence base does not say these types of programme don’t work but that we don’t have a robust evidence base from which to draw conclusions.
Conclusions
Helpfully the review concludes that there are some common features across successful interventions, which are summarised below. The characteristics of successful interventions align broadly with principles of behaviour change frameworks used in other settings such as public health. These principles reflect the need to create capability for change (physical/psychological ability to change), opportunity (external factors making change possible) and motivation (cognitive processes inspiring change). These are the characteristics of successful programmes.
- They are not solely punitive. Research shows little positive treatment effects for punitive interventions, unless alongside rehabilitation.
- They build skills which help people behave differently in the future. This is supported by behaviour change principles; people need not only motivation and opportunity to change, but also capability.
- They help develop pro-social identities. Development of a non-criminal identity helps people reintegrate into society. Maintaining a criminal identity can lead people to feel “doomed to deviance”.
- They use the principles of Risk-Need-Responsivity. Interventions matching level of treatment to the risk of reoffending and targeting criminogenic needs are more effective at reducing reoffending than those which do not.
- They target factors linked to offending. As above, interventions targeting linked criminogenic needs reduce reoffending.
- They develop intrinsic motivation to change. Behaviour change is most likely to be sustained when resulting from personal desire. Interventions placing external pressure on individuals to change without developing intrinsic motivation may be less successful.
- They are implemented in accordance with the specification. Evidence shows programme integrity is related to reductions in reoffending.
The review also notes that there is a wider context covering pre-conditions for good rehabilitation. This includes quality leadership, organisational structures, partnership working, etc. The evidence base for these pre-conditions was out of scope for the purposes of this MoJ synthesis. However, where there is evidence an intervention is effective, the review concludes that it is likely these pre-conditions have been addressed.
Thanks to Andy Aitchison for kind permission to use the header image in this post. You can see Andy’s work here
