3. Reimprisonment rates among men who inject drugs in Victoria, Australia

Reimprisonment is common among people in prison. While evidence suggests reimprisonment following release is particularly high among people who use drugs, there is little longitudinal data describing reimprisonment incidence in this group. We estimate reimprisonment rates among men with histories of injecting drug use (IDU) in Victoria, Australia.

Data from a cohort study (N=400) of men in prison with histories of IDU recruited between 2014-2016 were linked retrospectively to administrative imprisonment data. Men were included if self-reported IDU initiation occurred prior to their first adult imprisonment (n=33 excluded). Reimprisonment was defined as any reimprisonment during 2000–2016. Personyears (PY) was calculated from date of first prison release between 2000–2016, until 31- December-2016; time spent in prison excluded. Overall reimprisonment incidence rate (IR) was calculated as total reimprisonments/total PY. IRs were stratified by age at reimprisonment and calendar year.

Among 367 men, median age of first imprisonment was 26 years. Men contributed 1755 reimprisonments (from 328 men, 89%) and 2199.9 PY in community; median reimprisonment sentence length was 147 days. The reimprisonment IR was 79.8/100PY (95%CI=68.1–84.1) and was highest among men aged <20 years (242.5/100PY: 95%CI=150.8–390.2) and lowest among men aged ≥40 (54.3/100PY: 95%CI=48.6–60.7) at reimprisonment. Annual reimprisonment IRs ranged 113.5/100PY (95%CI=75.4–170.7) in 2000 to 47.8/100PY (95%CI=40.2–56.7) in 2016.

We found high rates of reimprisonment among men who inject drugs, with reimprisonment highest among younger men. Higher annual reimprisonment rates may be explained by more recent criminal justice policy reform, including changes to bail and parole legislation.