Prevalence of recent fentanyl use among treated users of illicit opioids in England: based on piloted urine drug screens.

Objective: To use a pilot of national fentanyl screening to establish the current prevalence of recent fentanyl use among treated users of illicit opioids in the English treatment system and inform the design of a full study.

Design: Cross-sectional fentanyl metabolite urine screening in randomly-selected study sites, stratified to cover all nine geographical regions of England, supplemented with self-report subsequent to a positive fentanyl test.

Patients: 468 adult (18 years of age and above) patients receiving treatment for opioid use disorder, screened December 2017 to May 2018.

Results: The fentanyl-positive rate in patients receiving treatment for opioid use disorder in the English treatment system was 3% (15/468, 95% CI 1.8% to 5.2%) with a per-site range (for the 10 sites in 9 regions where fentanyl was detected) of between 2% (1/57) and 15% (4/27). Self-report data indicated that the majority of fentanyl-positives (12/15, 80%) was unaware of having purchased fentanyl.

Conclusions: Despite alerts already in place, patients receiving treatment for opioid use disorder, who were fentanyl-positive, were unwittingly purchasing and consuming fentanyl.