14 May 2026
Mike Trace, CEO of The Forward Trust, reviews a new government report that analyses the outcomes of prison leavers in England (between August 2018 and December 2022) receiving substance misuse treatment. Mike explains how this reopens the debate about whether there should be ‘free’ drugs prescribed to prisoners, as part of a well established public health measure called Opiate Substitution Treatment (OST).
A recent report from the government’s BOLD (Better Outcomes through Linked Data) initiative has looked at post-custody death rates for prisoners with drug/alcohol problems.
The study matched individuals across three data sets – the MOJ Offender Management Database (p-NOMIS), the national Mortality Register (ONS), and the national drug/alcohol treatment monitoring database (NDTMS).
The focus of the report is on outcomes for released prisoners with a history of treatment for opiate use – a cohort of 66,344 individuals across the 4 year period.
The headline findings reported on this cohort are:
· While being in treatment for opiate use was associated with a generally higher post release mortality rate than other cohorts (0.21 deaths per 100 prison leavers), receiving OST on their final day in prison was associated with a 50% reduced risk of all-cause mortality and a 54% reduced risk of drug-related mortality in the 4 weeks following release, compared with opiate users who had not received OST on their final day.
· Receiving OST in prison was also associated with a 19% increased risk of returning to prison within 4 weeks of release, compared with other cohorts (itself an interesting finding, but not my focus here).
The finding on mortality rates would seem to back up earlier research (for example Marsden et al 2017) that indicates that enrolment on OST in prison reduces the risk of mortality on release. From the perspective of managing services in prisons, I would broadly agree that making OST more available in prison over the last 15 years has had the desired effect of protecting a proportion of prisoners from overdose risks.
But we need to be careful not to overstate the impact, nor to design services based on a misunderstanding of the complexities behind these figures. I have seen coverage of the findings of this research that seem to interpret them as a simple call to get more prisoners on to OST, including the practice of ‘re-toxing’ individuals, who have not been on OST during their time in prison, in the final days before release. It is not that simple, for many reasons:
1. Not included in the headlines around this research is the finding that the post-release mortality rate is highest amongst people receiving treatment for opiate use in prison. That is hardly surprising, as this cohort are by definition opiate users, and most drug related deaths are the result of opiate overdoses. But it is still the reality that most of this cohort will have been on OST, but still the death rate is worryingly high. Being on OST reduces the risk, but doesn’t eliminate it.
2. The reporting of the study focuses on a simple differentiator – whether individuals were receiving OST on the day of release (reasonably assumed to indicate that they were still engaged in treatment at that point), and finds that the ‘receiving OST’ cohort had a lower mortality rate than the ‘not receiving OST’ cohort (around 50% of whom were prisoners who had discontinued their OST treatment in prison, and 50% who were receiving some other type of intervention). But the numbers are small – the analysis is based on a total of 293 deaths of people in the four weeks after prison release, across the four years of the research period, and only 182 of these deaths were categorised as drug related. The impact of prison OST on the number of deaths in the 4 weeks post release is therefore an average of just over 20 deaths prevented per year. An important benefit but, in the context of the overall drug related death rate of over 5,000 per year, not a transformational figure.
3. Also unexamined in the report is the issue of compliance with OST. The ideal model for OST is that the individual is prescribed an adequate dose that enables them to cease use of street drugs, and benefit from the increased stability, and reduced associated risks. But we know that a proportion of people on OST do not comply with treatment – continuing to use opiates or other drugs on top of their prescription, or continuing risky or illegal behaviours despite receiving OST. Research on OST in prison does not give us any insight into the rate of non-compliance, but It is reasonable to assume that these ‘non-compliers’ are the ones most at risk of post-release overdose.
4. Similarly, some prisoners no longer receiving OST at point of release will have gone through a planned detox process and be making good progress in recovery, while others would be no longer receiving OST because they prefer to continue using illegally obtained drugs.
5. The finding that receiving OST on the day of release is associated with lower post-release death rates could therefore be explained by the higher number of more stable and compliant patients in that cohort who, it is reasonable to assume, are less likely to indulge in uncontrolled and risky patterns of use when returning to the community.
Such an interpretation fits more closely with my experience of working with drug users in prisons. Prisoners who engage well with OST certainly do use it to help them stay away from the illegal market, and stabilise their lives. But many others just see the prescribed drug as part of their cocktail of substances, and continue the addictive pattern of behaviour. On the other hand, many people who use their time in prison to detox and pursue abstinence based recovery are able to avoid overdose risk by the simple fact of not using drugs any more – but of course, some of this group are also exposed to greater risk if they relapse following a reduction in tolerance.
So, for me, it is not about prioritising OST over recovery, or vice versa, but of professionals having an honest conversation with prisoners about compliance – will they be able to remain stable on OST, or do they have the motivation and recovery capital to achieve recovery in prison. Both pathways, when they work, reduce risk - but forcing square pegs into round holes only achieves the opposite.
