The authors of this meta-analysis analyze the effects of treatment for male sexual offenders to reduce recidivism, in order to provide robust estimates of overall and differential treatment effects; they provide a brief summary before discussing their review process, data collection and analysis, and results.
This review integrates findings from six experimental and 21 quasi-experimental studies that compare groups of treated sexual offenders with equivalent control groups. These studies tested whether treated sexual offenders differed from the control groups in sexual and other reoffending. Included studies compare official recidivism rates of treated sexual offenders with a comparable group of sexual offenders that have not been subjected to the respective treatment. Quasi-experimental studies were included only if they applied sound matching procedures, where the incidental assignment would not introduce bias, or where they were statistically controlled for potential biases. The treatment had to explicitly aim at reducing recidivism rates. No studies on pharmacological/hormonal treatment were found which meet the inclusion criteria. On average, there is a significant reduction in recidivism rates in the treated groups. The odds to sexually reoffend were 1.41 lower for treated compared to control groups. This equals a sexual recidivism rate of 10.1 percent for treated offenders compared to 13.7 percent without treatment. The mean rates for general recidivism were higher but showed a similar reduction of roughly a quarter due to treatment. The results from the individual studies were very heterogeneous, and individual study features had a strong impact on the outcomes. Cognitive-behavioral studies, as well as studies with small samples, medium-to-high-risk offenders, more individualized treatment, and good descriptive validity revealed better effects. There was no significant difference between the various settings. The authors found significant effects for treatment in the community and in forensic hospitals but found insufficient evidence to draw conclusions regarding the effectiveness of sex offender treatment in prisons. Publisher Abstract Provided