Descriptive before-and-after study of the introduction of a ‘Leave Behind’ take-home naloxone dispensing/distribution program by the ambulance service in Western Australia

To describe changes observed in case characteristics and patient outcomes before and after ambulance service participation in a ‘Leave Behind’ take-home naloxone (THN) dispensing/distribution program. This before-and-after study included emergency ambulance attendances for patients experiencing an opioid overdose one year before 1 October 2021 (pre-participation phase: 1 October 2020–30 September 2021) when St John Western Australia (SJWA) participated in the THN program and those one year after the date (post-participation phase: 1 October 2021–30 September 2022). There were 945 and 1240 opioid overdoses among 221,451 and 222,480 emergency ambulance attendances in the pre- and post-participation phases (0.43% vs 0.56%, p < 0.001). The number of ambulance attendances for overdose in the post-participation phase was not significantly different from that predicted based on the ambulance attendances in the pre-participation phase. No statistically significant differences in patient age, sex, and geographical location were identified between the two phases. Compared to the pre-participation phase, more patients had naloxone administered prior to ambulance arrival (10.7% vs 15.1%, p = 0.003), and more patients were discharged at the scene (21.2% vs 29.8%, p < 0.001) in the post-participation phase. No difference was found in mortality within one day (3.4% in the pre-participation phase vs 3.5% in the post-participation phase, p = 0.30). After implementation of a ‘Leave Behind’ take-home naloxone dispensing/distribution program, more patients had naloxone administered prior to ambulance arrival, and the likelihood of discharging a patient at the scene significantly increased without affecting patient survival rates.