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Sexual offender treatment for reducing recidivism among convicted sex offenders

Additional Info

  • Authors: Martin Schmucker, Friedrich Loesel
  • Published date: 2017-07-31
  • Coordinating group(s): Crime and Justice
  • Type of document: Review, Plain language summary
  • Title: Sexual offender treatment for reducing recidivism among convicted sex offenders
  • Library Image: Library Image
  • See the full review: https://onlinelibrary.wiley.com/doi/10.4073/csr.2017.8
  • Records available in: English, Spanish
  • English:

    PLAIN LANGUAGE SUMMARY

    Treatment of sexual offenders reduces reoffending, but more research needed to identify effective interventions

    Treatment can reduce reoffending (recidivism) rates of sexual offenders. But the results of individual studies are too heterogeneous to draw a conclusion on the general effectiveness of sex offender treatment.

    What is this review about?

    Sexual offender treatment programs to reduce reoffending have been implemented in many countries as part of a strategy in managing this offender group. However, there are still controversies regarding their effectiveness.

    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.

    What is the aim of this review?

    This Campbell systematic review examines the effectiveness of treatment for sexual offenders to reduce reoffending and the factors that affect treatment success. The review summarises evidence from 27 impact evaluations.

    What studies are included?

    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.

    The review summarizes 27 studies containing 29 eligible comparisons of a treated group and a control group, containing data for 4,939 treated and 5,448 untreated sexual offenders. The studies come from seven different countries, but more than half of the studies have been carried out in North America. All eligible comparisons evaluated psychosocial treatment (mainly cognitive behavioral programs). No studies on pharmacological/hormonal treatment were found which meet the inclusion criteria.

    What are the main findings of this review?

    Does treatment of sexual offenders reduce recidivism?

    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, that is individual study features had a strong impact on the outcomes. Methodological quality did not significantly influence effect sizes. Cognitive-behavioral 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 various settings. We found significant effects for treatment in the community and in forensic hospitals, but there is not yet sufficient evidence to draw conclusions regarding the effectiveness of sex offender treatment in prisons.

    What do the findings in this review mean?

    Overall, the findings are promising, but there is too much heterogeneity between the results of individual studies to draw a generally positive conclusion about the effectiveness of sex offender treatment. Applied cognitive-behavioral foundation of treatment has relatively good potential, but other features, like the risk of the treated offenders or including individualized treatment, significantly affect treatment success.

    More well documented randomized trials and high-quality quasi-experiments are needed, particularly outside of North America. In addition, there is a clear need of more differentiated process and outcome evaluations.

    How up-to-date is this review?

    The study pool of the present analysis was based on the broad search of 2,039 documents from a review published in 2005, updated to cover studies issued prior to 2010. More recent studies were evaluated in an appendix and mostly showed similar findings as in our review.

  • Spanish:

    Click on 'Download PDF' on the right to view the plain language summary in Spanish.

Select language:

PLAIN LANGUAGE SUMMARY

Treatment of sexual offenders reduces reoffending, but more research needed to identify effective interventions

Treatment can reduce reoffending (recidivism) rates of sexual offenders. But the results of individual studies are too heterogeneous to draw a conclusion on the general effectiveness of sex offender treatment.

What is this review about?

Sexual offender treatment programs to reduce reoffending have been implemented in many countries as part of a strategy in managing this offender group. However, there are still controversies regarding their effectiveness.

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.

What is the aim of this review?

This Campbell systematic review examines the effectiveness of treatment for sexual offenders to reduce reoffending and the factors that affect treatment success. The review summarises evidence from 27 impact evaluations.

What studies are included?

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.

The review summarizes 27 studies containing 29 eligible comparisons of a treated group and a control group, containing data for 4,939 treated and 5,448 untreated sexual offenders. The studies come from seven different countries, but more than half of the studies have been carried out in North America. All eligible comparisons evaluated psychosocial treatment (mainly cognitive behavioral programs). No studies on pharmacological/hormonal treatment were found which meet the inclusion criteria.

What are the main findings of this review?

Does treatment of sexual offenders reduce recidivism?

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, that is individual study features had a strong impact on the outcomes. Methodological quality did not significantly influence effect sizes. Cognitive-behavioral 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 various settings. We found significant effects for treatment in the community and in forensic hospitals, but there is not yet sufficient evidence to draw conclusions regarding the effectiveness of sex offender treatment in prisons.

What do the findings in this review mean?

Overall, the findings are promising, but there is too much heterogeneity between the results of individual studies to draw a generally positive conclusion about the effectiveness of sex offender treatment. Applied cognitive-behavioral foundation of treatment has relatively good potential, but other features, like the risk of the treated offenders or including individualized treatment, significantly affect treatment success.

More well documented randomized trials and high-quality quasi-experiments are needed, particularly outside of North America. In addition, there is a clear need of more differentiated process and outcome evaluations.

How up-to-date is this review?

The study pool of the present analysis was based on the broad search of 2,039 documents from a review published in 2005, updated to cover studies issued prior to 2010. More recent studies were evaluated in an appendix and mostly showed similar findings as in our review.

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See the full review

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