Engagement with the criminal justice system among opioid-dependent people: a retrospective cohort study (2013)

Aims: Studies of offending among people who use drugs typically focus upon small and potentially unrepresentative samples. We examined an entire population of opioid-dependent clients' contact with the criminal justice system to develop more accurate population-wide measures of offending among opioid-dependent people in Australia.
Design: Retrospective data linkage study.
Setting: All entrants to opioid substitution therapy (OST) for opioid dependence in New South Wales, Australia, between 1985 and 2010, with data on court appearances from 1 December 1993 to 31 March 2011.
Participants: All 48 069 valid cohort members who received OST between 1985 and 2010.
Measurements: Person-years (PY) of observation and charge rates for major crime categories estimated by sex, age and time.
Findings: A total of 638 545 charges were laid against cohort members between 1993 and 2011. Eight in 10 males (79.7%) and 67.9% of females had at least one charge; rates were 94.15 per 100 PY [95% confidence interval (CI) = 93.89-94.41] among males, and 53.19 per 100 PY (95% CI = 52.91-53.46) among females, and highest at 15-19 years [175.74/100 PY males (95% CI = 174.45-177.03), 75.60/100PY females (95% CI = 74.46-76.76)] and 20-24 years [144.61/100 PY males (95% CI = 143.70-145.53), 84.50/100 PY females (95% CI = 83.53-85.48)]. The most frequent charges were theft (24.5% of charges), traffic/vehicle (16.3%), offences against justice (10.5%), illicit drug (10.0%), intentional injury (9.9%) and public order offences (8.9%). Overall, 20.8% of the cohort accounted for 67.4% of charges. The most frequently appearing 5.6% of the cohort accounted for 24.3% of costs ($75.5 million).
Conclusions: Among opioid-dependent people in Australia, a minority account for the majority of the criminal justice contact and levels of offending are not consistent over time, sex or age.