Cost-effectiveness of extended release naltrexone to prevent relapse among criminal justice-involved individuals with a history of opioid use disorder

Abstract

Background and aims: Criminal justice-involved individuals are highly susceptible to opioid relapse and overdose-related deaths. In a recent randomized trial, we demonstrated the effectiveness of extended-release naltrexone (XR-NTX; Vivitrol^® ) in preventing opioid relapse among criminal justice-involved US adults with a history of opioid use disorder. The cost of XR-NTX may be a significant barrier to adoption. Thus, it is important to account for improved quality of life and downstream cost-offsets. Our aims were to (1) estimate the incremental cost per quality-adjusted life-year (QALY) gained for XR-NTX versus treatment as usual (TAU) and evaluate it relative to generally accepted value thresholds; and (2) estimate the incremental cost per additional year of opioid abstinence.

Design: Economic evaluation of the aforementioned trial from the taxpayer perspective. Participants were randomized to 25 weeks of XR-NTX injections or TAU; follow-up occurred at 52 and 78 weeks.

Setting: Five study sites in the US Northeast corridor.

Participants: A total of 308 participants were randomized to XR-NTX (n = 153) or TAU (n = 155).

Measurements: Incremental costs relative to incremental economic and clinical effectiveness measures, QALYs and abstinent years, respectively.

Findings: The 25-week cost per QALY and abstinent-year figures were $162 150 and $46 329, respectively. The 78-week figures were $76 400/QALY and $16 371/abstinent year. At 25 weeks, we can be 10% certain that XR-NTX is cost-effective at a value threshold of $100 000/QALY and 62% certain at $200 000/QALY. At 78 weeks, the cost-effectiveness probabilities are 59% at $100 000/QALY and 76% at $200 000/QALY. We can be 95% confident that the intervention would be considered 'good value' at $90 000/abstinent year at 25 weeks and $500/abstinent year at 78 weeks.

Conclusions: While extended-release naltrexone appears to be effective in increasing both quality-adjusted life-years (QALYs) and abstinence, it does not appear to be cost-effective using generally accepted value thresholds for QALYs, due to the high price of the injection.

Keywords: Cost-effectiveness; criminal justice populations; extended release naltrexone; opioid use disorder; quality-adjusted life-years; time abstinent.