Why is the government continuing to spend thousands of pounds on programmes aimed at reducing domestic abuse when they don't know whether they work? Today Transform Justice brings out a report on reducing domestic abuse which advocates for greater use of perpetrator programmes to reduce domestic abuse. But it's only worth using perpetrator programmes which work.

Domestic abuse is a complicated problem. For some perpetrators it is a deeply ingrained coercive behaviour, while others may have a one off fit of temper. Some people abuse family members, others their partners. Perpetrator programme are all designed to change the attitudes and behaviour of abusers.

Any ingrained criminal behaviour is difficult to shift and the evidence on domestic abuse is mixed. The results of international randomised controlled trails show that programmes have no long term impact on abuse. But some programmes do work

If course participants are interviewed before they start the course by someone trained in motivational interviewing, their offending is reduced.

Accredited courses delivered in the community have been demonstrated to reduce abuse. Participants attended voluntarily, having referred themselves, or been referred by social services. Victims were asked how their partners' behaviour had changed. 30% of women victims involved in the programme reported being made to ‘do something sexual’ they did not want to do in the three months before the programme started. That was reduced to zero a year after starting the programme. Similarly, victims who reported having a weapon used against them reduced from 29% to zero.

IDAP, a programme designed for those who had been convicted of domestic abuse, was delivered by probation and prison staff. An evaluation published in 2015 showed the programme to be successful in reducing abuse, but the programme had fallen out of favour by the time the results were published.

Probation and prison staff now deliver two completely different domestic abuse programmes - Building Better Relationships and Kaizen. They also delivered a programme called Healthy Relationships in prison for 14 years. The problem with the programmes currently being delivered as part of criminal sentences is that none of them have been evaluated. They are accredited, but that just seems to mean that their design has been approved by an expert committee and a commitment has been made to evaluate them at some stage. So how on earth do we know that these particular programmes are effective. The cautionary tale of the Core Sex Offender Treatment Programme shows why we need to evaluate programmes. From 1992, sex offenders in prison were referred to the programme, which was adapted slightly over the years but not re-evaluated. In 2016, over 20 years after the programme started, researchers found that the course was in fact exacerbating the risk of participants offending after being released from prison.

Healthy Relationships ran for many years, but was never evaluated. Building Better Relationships has been running since 2012 in prisons and probation and no evaluation of it has even got off the ground. This is a real worry, particularly since the way programmes are delivered can influence their success. The programmes which are currently part of criminal sentences may be doing more harm than good. Who knows?

This really matters because we know that criminal sanctions don't on the whole work to reduce domestic abuse. We need to reappraise our use of criminal sentences to put more emphasis on out of court disposals and approaches, but also to focus on making criminal sanctions work better. To know whether any programmes work, we need to evaluate them properly.