BACKGROUND AND AIMS: Connections is a voluntary health program that facilitates access to opioid agonist treatment (OAT) and social services for people with opioid use exiting prison. This study aimed to measure the effectiveness of Connections in reducing recidivism and improving health outcomes for people with a history of opioid use on leaving prison.

DESIGN: Retrospective cohort study with quasi-random allocation to the program, taking place in public adult prisons in New South Wales, Australia, 2008-2015.

PARTICIPANTS: Adults released from custody with a history of opioid use. Of 5549 eligible releases, 3973 were allocated to Connections and 1576 to treatment-as-usual.

MEASUREMENTS: Outcomes were return-to-custody, all-cause mortality, and OAT participation.

FINDINGS: Regression analyses on an intention-to-treat basis, and adjusting for baseline propensity scores, comparing patients allocated to Connections versus treatment-as-usual showed no difference in rates of return-to-custody within 2 years. Patients allocated to the Connections program were more likely to access OAT and had lower mortality within 28 days of release. Differences in mortality did not persist beyond 28 days. Subgroup analyses showed that allocation to Connections was associated with higher risk of return-to-custody within 28 days for Aboriginal and/or Torres Strait Islander (Indigenous) and female releases.

CONCLUSIONS: The Connections program for people with opioid use exiting prison did not reduce the likelihood of return-to-custody but did facilitate opioid agonist treatment participation on release from prison.