Improving methadone maintenance therapy for prisoner populations

What is already known on this topic

Methadone maintenance is effective at reducing the harmful behaviours associated with illicit opioid use.1 The weight of evidence from intervention and observational studies highlights that being prescribed methadone maintenance leads to a reduction in mortality, heroin use, injecting and criminal activity.1 ,2 However, exposure to methadone maintenance is inversely related to a user's chances of achieving long-term cessation and therefore long-term prescribing remains contentious.2 Methadone programmes can be implemented safely in prison settings, yet internationally there are significant political and cultural barriers to maintaining drug users on methadone therapy following reception into prison.3

Methods of the study

This was a randomised open label controlled trial. The study participants were male and female prisoners of Rhode Island Department of Corrections, USA, who had been receiving methadone maintenance treatment in the community prior to their incarceration.

Participants were included in the study if: they were receiving methadone maintenance treatment; they were willing to be randomly assigned to the intervention or control group; their length of incarceration was more than 1 week but less than 6 months; they were English or Spanish speaking; they intended on continuing methadone maintenance treatment throughout incarceration and on release into the community. Exclusion criteria included any of the following: pregnant women; HIV-positive status; length of incarceration of less than 1 week or more than 6 months; had already started the tapered withdrawal procedure. The data were collected between June 2011 and April 2013. During this period, 506 prisoners were screened for eligibility; of which 283 were randomised. Following withdrawals and further exclusions due to ineligibility, 223 were eligible to participate, 114 of which were allocated to the methadone continuation group and 109 to the mandatory withdrawal group. The intervention was the continuation of methadone maintenance treatment during imprisonment and the control group was usual care (ie, mandatory withdrawal). Participants were randomly allocated on a 1:1 ratio through the utilisation of a computer random number generator. Urn randomisation procedures were adopted to stratify individuals according to sex and ethnicity.

The primary outcome was engagement with a community methadone maintenance treatment facility following release from custody and length of time to engagement with methadone maintenance treatment. Secondary outcomes included use of illicit drugs (particularly opioids), incidence of reported HIV risk behaviours, undertaking a drug treatment programme, re-imprisonment and cost of healthcare. One month after release from custody, all participants’ community clinic methadone records were checked and face-to-face interviews were conducted with participants where possible; 88% of participants attended the follow-up interview.

What does this paper add

• Rich and colleagues’ study is the first prison-based randomised controlled trial exploring the effectiveness of methadone maintenance therapy on treatment engagement postrelease from prison.

• Prison-based methadone maintenance therapy was effective in both retaining participants in community drug treatment and in reducing opioid use at 1-month postrelease from prison (96% in the continued methadone group vs 78% in the forced withdrawal group returned to community treatment at 1-month follow-up; adjusted HR 2.04 (95% CI 1.48 to 2.8).

Limitations

• Participants were recruited from a single prison and the inclusion criteria limited recruitment to prisoners serving more than 1 week but less than 6 months (it is not possible to conclude whether such exclusion criteria overestimated or underestimated the true effectiveness of methadone). The findings are not generalisable to all opioid-dependent prisoners.

• Follow-up of participants postrelease was limited to a 1-month time period.

What next in research

• Long-term prospective cohort studies following up patients in receipt of methadone maintenance postrelease from prisons are needed to quantify the effect of methadone maintenance therapy on mortality, illicit drug use, injecting practice, criminal behaviour and re-imprisonment.

• The factors that contribute to prison healthcare culture and practice need to be explored further through qualitative research across a variety of differing prison settings.

Do these results change your practices and why?

Yes. The period following prison release is a high-risk time for fatal heroin overdose among patients with a history of opioid dependence who are released abstinent and not engaged in community drug treatment services. Methadone maintenance therapy has the potential to reduce the risk of fatal heroin overdose. Therefore, opioid-dependent prisoners should not be forced to undergo withdrawal against their consent. Methadone maintenance should be offered with ongoing support to achieve abstinence at a time and pace that is optimal for the individual. Some users will require many years of therapy and so it should be continued at times of reception into and release from prison.