A quasi-experimental evaluation of a specialized treatment service for youth adjudicated for sexual offences in Queensland, Australia

This study presents a quasi-experimental evaluation of a specialized treatment program for young people in Australia who have committed sexual offences. Using administrative data from Queensland's Department of Youth Justice and Victim Support, the study examined 1489 young people processed for sexual offences between 2010 and 2024, 286 of whom were referred to and received treatment at a specialized service in the state. Covariate-adjusted and propensity score-based methods, along with Cox regression analysis, were used to assess treatment effects on violent, non-violent, and sexual recidivism for 144 young people who received treatment from the service and 303 who did not. Results indicate that treatment reduced overall recidivism by 34 %–44 %, with the greatest reductions observed in sexual recidivism (78 %–90 %). These findings support the effectiveness of specialized treatment for young people who have committed sexual offences. The implications of methodological decisions in quasi-experimental research designs with this population are also discussed. • Specialized evidence-based interventions may help reduce non-sexual recidivism among young people who perpetrate sexual offences. • The impact of specialized treatment services on reducing sexual recidivism specifically is less clear. • The current quasi-experimental study indicates that specialized treatment reduced general and sexual recidivism. • The findings also demonstrate the importance of control group composition in quasi-experimental designs.