Use of contingency management (positive reinforcement with financial incentives) to encourage abstinence from heroin (PRAISE): a UK cluster randomised trial
Background: Contingency management (CM) is a behavioural intervention based on the principles of operant conditioning; it uses positive reinforcement such as financial incentives to encourage positive behaviour change. There is a growing evidence base for its effectiveness but mainly from the US. There has been little research on CM in the UK. The presenters have already demonstrated that CM can effectively promote distinct short-term behaviour change (completion of Cluster RCT of CM targeted at hepatitis b vaccination). The trial reported here shifted the focus towards longer-term change in drug-using behaviour.
Methods: This cluster trial aimed to assess whether CM is effective at promoting and sustaining longer term behaviour change; specifically, whether CM is effective at encouraging abstinence from heroin among individuals receiving opiate substitution treatment (OST). A cluster randomised controlled trial was conducted at 33 sites in England to assess the effectiveness of CM (praise with modest financial incentives) - targeted at either (i) abstinence from heroin or (ii) attendance at keywork sessions - at reducing heroin use among individuals receiving OST. Sites delivered OST and 12 weekly keywork sessions and were randomly allocated to deliver either (a) CM Abstinence – reinforcement for attending weekly keywork sessions on time and providing urine samples negative for opiates; (b)CM Attendance – reinforcement for attending keywork sessions on time only; or (c) the comparison condition of no CM . As a cluster randomised trial, participants received the treatment their site was assigned to. The primary outcome was the number of urine samples negative for heroin between weeks 9-12. Extended follow-up 12 weeks after cessation of CM (weeks 21-24) was undertaken to assess whether any benefits at weeks 9-12 had been sustained.
Results: Findings showed that participants who received (b) CM Attendance were twice as likely to provide heroin-negative urine samples during weeks 9-12 compared to (c) no CM (with a statistically significance difference). No statistically significant difference was found for (a) CM Abstinence compared with (c) No CM. The benefits were not sustained at 21-24 weeks.
Conclusions: Findings from the extended long term follow-up and embedded process evaluation including treatment fidelity, and experiences of staff and service users will also be presented. Clinical and policy implications of the findings will be discussed.