What Patient Characteristics Might Predict Successful Treatment Outcomes for Opioid Use Disorder?

Key points:

• Figuring out what patient characteristics might predict successful treatment for OUD can help clinicians better individualize treatment plans
• Medications for opioid use disorder are the most effective treatment for this condition but remain underused
• In this study, demographic characteristics like race/ethnicity, educational background, housing, etc. seemed to have little impact on outcomes (possibly because of study design)
• Factors that did improve outcomes included: staying on treatment medication longer, having early success with abstinence, and taking injectable naltrexone instead of buprenorphine-naloxone (though fewer patients were successfully inducted onto naltrexone, resulting in overall higher relapse rates in that group)

The opioid crisis continues to be a major challenge in the United States, with over 100,000 drug overdose deaths in 2021, most of which involved opioids – an increase of nearly 30% over the previous year.

Medications for opioid use disorder (MOUD) remain the most effective treatments for this condition yet continue to be underused, difficult for many patients to access, and sometimes challenging for patients to stick with. 

Figuring out what patient characteristics might predict successful treatment for opioid use disorder (OUD) is important, as it can help clinicians better individualize treatment plans. 

This study used data from the NIDA Clinical Trials Network X:BOT protocol (CTN-0051), which compared extended-release injectable naltrexone (XR-NTX) to buprenorphine-naloxone (BUP-NX) for OUD treatment, to try to figure out what factors – demographics, clinical characteristics, and treatment elements – might predict successful opioid abstinence.  

Of the 428 participants, 33% reported abstinence from non-prescribed opioids at the 36-week follow-up. Demographic factors were not significantly associated with opioid abstinence at follow-up in this study – possibly because those factors (race/ethnicity, housing, educational background, legal status, etc.) tend to influence treatment engagement and outcomes more in the naturalistic setting rather than in a controlled setting in a research study. 

However, several treatment factors did influence outcomes. For example, participants were more likely to be opioid-abstinent at 36 weeks if they:

• were randomized to XR-NTX (compared to BUP-NX; 44% vs. 24%)
• were on XR-NTX at week 36 (compared to those who had stopped taking any MOUD)
• had been successfully inducted onto either study medication (36% vs. 15%) 
• were on study medication longer
• reported more weeks of successful abstinence during the study period

Conclusions: People who stayed on their medication, had success with abstinence early in treatment, and were taking injectable naltrexone appeared to have better outcomes than those who went off their medication or were taking buprenorphine-naloxone (though it’s important to note that there was a substantial induction hurdle for naltrexone in the parent study, with 28% of patients randomized to that group dropping out before starting the medication, compared to just 6% in the buprenorphine group, and nearly all induction failures experienced early relapse). More research is needed to explore patient characteristics that might be associated with successful treatment for OUD, but these results may help inform interventions and better personalize treatment plans.

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