Summary
Aim
To determine whether the NSW Juvenile Justice Intensive Supervision Program (ISP) is more effective than conventional case management in reducing the frequency of offending among young people.
Method
Using a non-equivalent groups design, offending frequency over a 48-month period is examined for three groups of offenders; ISP graduates (those who signed up to and completed ISP), ISP terminates (those who signed up to but did not complete ISP) and a comparison group (those who received a supervised community order or a court-referred Youth Justice Conference in locations where ISP was not available). Days spent in custody over this 48-month period are also examined for each of these three groups. Time-series models are used to assess changes in offending frequency and days in custody during the 6 and 12 month periods after the intervention. Multilevel models are also used to test for group differences in offending frequency during the post intervention period after controlling for other factors.
Results
Multilevel modelling showed a significant reduction in offending frequency during and after the intervention period for both ISP graduates and the comparison group, but the rate of decrease was not significantly different across these two groups. The time-series analysis found a significant reduction in offending frequency in the 6 months after the intervention start date that was restricted to non-Indigenous ISP graduates and Indigenous offenders from the comparison group. For all other groups (Indigenous ISP graduates, all ISP terminates and non-Indigenous offenders from the comparison group), offending decreased in the latter part of the study period but this drop did not coincide with commencement of the intervention. For the ISP graduates only, there was a significant reduction in days spent in custody during the 6-month intervention period. Nevertheless this downward trend was not sustained in the 6 months following program completion.
Conclusion
There is no evidence that ISP impacts the offending frequency of young people over and above the usual effect of a supervised order. However, there is good evidence that young people who complete ISP spend significantly fewer days in custody during their treatment program.