Death after residential treatment for opioid use disorder among people using fentanyl

Objectives: Drug overdose death is an ongoing public health crisis in North America, driven by the proliferation of fentanyl in the illicit opioid supply. Some people with opioid use disorder (OUD) prefer and seek fentanyl, while others view it as an unwelcome adulterant in the opioid supply.

Methods: Patients entering residential OUD treatment with buprenorphine between December 2019 through July 2021 with baseline fentanyl exposure (n=250) were enrolled in a study on fentanyl preferences. Participants were interviewed at treatment entry about their background, experiences, behaviors, and preferences regarding fentanyl and other opioids. Mortality after treatment was tracked using state death records, covering a period of 2.5-4 years post-treatment entry. Survival analysis methods (Kaplan-Meier, proportional hazards Cox regression) were used to characterize deaths and association with participant characteristics.

Results: Participants were 74% male and 60% Black, with a mean (SD) age of 42.9 (11.6) years. Death record searches identified 38 deaths in the sample (15.2%), of which 8 (21%) occurred within 90 days of leaving treatment. Most deaths were due to overdose (74%). Approximately 52% of participants expressed a preference for fentanyl (alone or mixed with heroin) compared to other opioids, with 21% preferring fentanyl alone. Mean (SD) length of treatment was 88.3 (84.6) days. Neither participant characteristics nor opioid preference predicted mortality.

Conclusion: The ubiquity of fentanyl in the opioid supply has created an environment where death is a relatively common outcome among people who use opioids. People with OUD remain at risk for overdose death after residential treatment, even with relatively long treatment episodes.