Cost-effectiveness implications of increasing the efficiency of the extended-release naltrexone induction process for the treatment of opioid use disorder: a secondary analysis.

Background and aims In a United States randomized-effectiveness trial comparing extended-release naltrexone (XR-NTX) with buprenorphine-naloxone (BUP-NX) for the prevention of opioid relapse among participants recruited during inpatient detoxification (CTN-0051), the requirement to complete opioid detoxification prior to initiating XR-NTX resulted in lower rates of initiation of XR-NTX (72%-XR-NTX vs. 94%-BUP-NX). This led to higher relapse rates and average healthcare costs among XR-NTX participants. This study estimated the extent to which a more efficient model of XR-NTX induction would improve the economic value of XR-NTX relative to BUP-NX. Design This was a retrospective secondary analysis of CTN-0051 trial data, including follow up data over 24-36 weeks. Setting Eight community-based, inpatient-detoxification and follow-up outpatient treatment facilities in the USA. Participants 283 participants randomized to receive XR-NTX. Measurements Efficiency was estimated using a multivariable generalized-structural-equation model to explore simultaneous determinants of XR-NTX induction and induction duration (detoxification + residential days). Cost-effectiveness was estimated from the healthcare sector perspective and included expected costs and quality-adjusted life-years (QALYs). Findings Treatment site was the only modifiable factor that simultaneously increased the likelihood of XR-NTX induction and decreased induction duration. Incorporating the higher predicted probability of XR-NTX induction, and fewer predicted days of detoxification and subsequent residential treatment into the cost-effectiveness framework, reduced the incremental average 24-week total cost of XR-NTX treatment from $5,317 more than that of BUP-NX (p=0.01) to a non-statistically-significant difference of $1,016 (p=0.63). QALYs gained remained similar across arms. Conclusion Adopting an efficient model of extended-release naltrexone initiation could result in extended-release naltrexone and buprenorphine-naloxone being of comparable economic value from the healthcare sector perspective over 24-36 weeks for patients seeking treatment for opioid use disorder at an inpatient detoxification facility.