Who reports witnessing an opioid overdose? : Findings from the European naloxone outcome research study (NalPORS)

Background: In response to rising opioid overdose (OD) deaths, Take-Home Naloxone (THN) programmes have been implemented in many European countries. Little research has investigated the characteristics of individuals who access drug treatment and harm reduction services, and are supplied with a THN kit and report witnessing an opioid OD.  Moreover, there is a lack of research examing  factors that may increase the likelihood of witnessing multiple ODs in one’s lifetime. The aim of this research was to investigate which demographic characteristics (age, gender, ethnicity, minority status, living situation, homelessness) and type of community member supplied with THN, are associated with higher OD witness rates, and if previous experience of witnessing an OD or administering naloxone to reverse an opioid OD, is associated with a higher likelihood of witnessing a subsequent ODs. 

Methods: A European, observational cohort study was conducted. Participants supplied with THN were recruited from treatment and harm reduction services in England, Wales, Scotland and Sweden between June 2021 and March 2024 and followed-up for 6 months.  They included: people who use opioids and were in treatment/out of treatment; friends, family members or carers, and staff working with people who use opioids. Participants witnessing an opioid OD during the six-month period were asked to complete a structured questionnaire about the event, administered by a researcher. One witnessed OD event was captured per participant.

Results: Between June 2021 and March 2023, 987 participants were supplied with THN, recruited to the study and followed-up for six months. Of these, 14% (139) reported witnessing an OD. A higher proportion of women (Pearson’s X2=5.07, df=1;p=0.024), those living with others (Pearson’s X2=6.34, df=1;p=0.01), and those experiencing homelessness (Pearson’s X2=19.08, df=1;p<0.001) reported witnessing an OD. Those who had previously witnessed an OD had increased odds of witnessing a subsequent OD (4.389; p<0.001, 95%CI (2.43, 7.95)), and previous experience of administering naloxone was associated with increased odds of witnessing an OD (3.870; p<0.001, 95%CI (2.267, 6.606)). Findings will be presented by country and type of recruitment site.

Conclusions: Data on community members most likely to witness opioid ODs can provide policymakers with the evidence needed to help target THN programmes to reach those most likely to witness multiple ODs.