A prospective study of retention in opioid agonist treatment and contact with emergency healthcare following release from prisons in Victoria, Australia.

Background: People recently released from prison engage with emergency healthcare at greater rates than the general population. While retention in opioid agonist treatment (OAT) is associated with substantial reductions in the risk of opioid-related mortality post-release, it is unknown how OAT may impact contact with emergency healthcare. In a cohort of men who injected drugs regularly prior to imprisonment, we described rates of contact with ambulance services and emergency departments, and their associations with use of OAT in the three months following release from prison.

Methods: Self-report data from a prospective observational cohort of men who regularly injected drugs before a period of sentenced imprisonment in Victoria, Australia, recruited between September 2014 and May 2016, were linked to statewide ambulance and emergency department records over a three-month post-release period. We used generalised linear models to estimate associations between OAT use (none/partial/retained) and contact with ambulance and emergency departments (ED) post-release, adjusted for other covariates.

Results: Among 265 participants, we observed 77 ambulance contacts and 123 emergency department contacts over a median of 98 days of observation (interquartile range: 87–125 days). Participants who were retained in OAT between prison-release and scheduled three-month post-release follow-up interviews had lower rates of contact with ambulance (Adjusted Incidence Rate Ratio [AIRR]: 0.35, 95% Confidence Interval [95%CI]: 0.15–0.79) and emergency departments (AIRR: 0.44, 95%CI: 0.22–0.85), compared to participants with no OAT use post-release. Partial OAT use across the observation period was not associated with rates of contact with ambulance or ED compared to no OAT use.

Conclusion: We found lower rates of contact with emergency healthcare post-release among people retained in OAT, but not among people reporting partial OAT use, underscoring the benefits of OAT retention post-release. Programs to increase access and support OAT retention are important among men leaving prison who inject drugs.