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

Abstract

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. Retrospective data linkage study. 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. All 48 069 valid cohort members who received OST between 1985 and 2010. Person-years (PY) of observation and charge rates for major crime categories estimated by sex, age and time. 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), 75.60/100 PY 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). 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.