Skip to main content

The effectiveness of treatment for sexual offenders: A comprehensive meta-analysis

Journal of Experimental Criminology volume 1, pages 117–146 (2005)Cite this article

Abstract

The article reports a meta-analysis on controlled outcome evaluations of sexual offender treatment. From 2,039 documents published in five languages, 69 studies containing 80 independent comparisons between treated and untreated offenders fulfilled stepwise eligibility criteria (total N = 22,181). Despite a wide range of positive and negative effect sizes, the majority confirmed the benefits of treatment. Treated offenders showed 6 percentage points or 37% less sexual recidivism than controls. Effects for violent and general recidivism were in a similar range. Organic treatments (surgical castration and hormonal medication) showed larger effects than psychosocial interventions. However, this difference was partially confounded with methodological and offender variables. Among psychological programs, cognitive–behavioral approaches revealed the most robust effect. Nonbehavioral treatments did not demonstrate a significant impact. There was no outcome difference between randomized and other designs, however, group equivalence was associated with slightly larger effects. Various other moderators had a stronger impact on effect size (e.g., small sample size, quality of outcome reporting, program completion vs. dropout, age homogeneity, outpatient treatment, and authors’ affiliation with the program). More differentiated, high-quality evaluations are needed to clarify: What works for whom under which circumstances?

This is a preview of subscription content, access via your institution.

Access options

Buy single article

Instant access to the full article PDF.

USD 39.95

Price includes VAT (USA)
Tax calculation will be finalised during checkout.

References

  • Alexander, M. A. (1999). Sexual offender treatment efficacy revisited. Sexual Abuse: A Journal of Research and Treatment 11, 101–116.

    Google Scholar 

  • Andrews, D. A., Bonta, J. & Hoge, R. D. (1990). Classification for effective rehabilitation. Criminal Justice and Behavior 17, 19–51.

    Google Scholar 

  • Aos, S., Phipps, P., Barnoski, R. & Lieb, R. (2001). The comparative costs and benefits of programs to reduce crime. Version 4.0 (Report No. 01-05-1201). Washington: Washington State Institute for Public Policy.

    Google Scholar 

  • Barbaree, H. (1997). Evaluating treatment efficacy with sexual offenders: The insensitivity of recidivism studies to treatment effects. Sexual Abuse: Journal of Research and Treatment 9, 111–128.

    Google Scholar 

  • Cohen, J. & Cohen, P. (1983). Applied multiple regression/correlation analysis for the behavioral sciences (2nd ed.). Hillsdale, NJ: Erlbaum.

    Google Scholar 

  • Cronbach, L. J., Ambron, S. R., Dornbusch, S. M., Hess, R. D., Hornik, R. C. & Phillips, D. C., et al. (1980). Toward a reform of program evaluation. San Francisco, CA: Jossey Bass.

    Google Scholar 

  • Farrington, D. P. (2003). Methodological quality standards for evaluation research. Annals of the American Academy of Political and Social Science 587, 49–68.

    Google Scholar 

  • Farrington, D. P. & Petrosino, A. (2001). The Campbell Collaboration Crime and Justice Group. Annals of the American Academy of Political and Social Science 578, 35–49.

    Google Scholar 

  • Farrington, D. P. & Welsh, B. C. (2003). Family-based prevention of offending: A metaanalysis. Australian and New Zealand Journal of Criminology 36, 127–151.

    Google Scholar 

  • Fedoroff, J. P. & Moran, B. (1997). Myths and misconceptions about sex offenders. Canadian Journal of Human Sexuality 6, 263–276.

    Google Scholar 

  • Fleiss, J. L. (1994). Measures of effect size for categorical data. In L. V. Hedges (Ed.), The handbook of research synthesis (pp. 245–260). New York: Russell Sage Foundation.

    Google Scholar 

  • Friendship, C., Mann, R. E. & Beech, A. R. (2003). Evaluation of a national prison-based treatment program for sexual offenders in England and Wales. Journal of Interpersonal Violence 18, 744–759.

    Google Scholar 

  • Furby, L., Weinrott, M. R. & Blackshaw, L. (1989). Sex offender recidivism: A review. Psychological Bulletin 105, 3–30.

    Google Scholar 

  • Gallagher, C. A., Wilson, D. B. & MacKenzie, D. L. (2000). A meta-analysis of the effectiveness of sex offender treatment programs. Retrieved 5/23/2001, from http://www.wam.umd.edu/∼wilsondb/papers/sexoffender.pdf.

  • Hall, G. C. N. (1995). Sexual offender recidivism revisited: A meta-analysis of recent treatment studies. Journal of Consulting and Clinical Psychology 63, 802–809.

    Google Scholar 

  • Hall, G. C. N. (1996). Theory-based assessment, treatment, and prevention of sexual aggression. New York: Oxford University Press.

    Google Scholar 

  • Hanson, R. K. & Bussière, M. T. (1998). Predicting relapse: A meta-analysis of sexual offender recidivism studies. Journal of Consulting and Clinical Psychology 66, 348–362.

    Google Scholar 

  • Hanson, R. K., Gordon, A., Harris, A. J. R, Marques, J. K., Murphy, W. D. & Quinsey, V. L., et al. (2002). First report of the collaborative outcome data project on the effectiveness of psychological treatment for sex offenders. Sexual Abuse: A Journal of Research and Treatment 14, 169–194.

    Google Scholar 

  • Hanson, R. K., Broom, I. & Stephenson, M. (2004). Evaluating community sex offender treatment programs: A 12-year follow-up of 724 offenders. Canadian Journal of Behavioural Sciences 36, 87–96.

    Google Scholar 

  • Hasselblad, V. & Hedges, L. V. (1995). Meta-analysis of screening and diagnostic tests. Psychological Bulletin 117, 167–178.

    Google Scholar 

  • Hedges, L. V. & Olkin, I. (1985). Statistical methods for meta-analysis. Orlando: Academic Press.

    Google Scholar 

  • Hucker, S. J. & Bain, J. (1990). Androgenic hormones and sexual assault. In W. L. Marshall, D. R. Laws & H. E. Barbaree (Eds.), Handbook of sexual assault: Issues, theories, and treatment of the offender (pp. 93–102). New York: Plenum Press.

    Google Scholar 

  • Lipsey, M. W. (2003). Those confounded moderators in meta-analysis: Good, bad, and ugly. Annals of the American Academy of Political and Social Science 587, 69–81.

    Google Scholar 

  • Lipsey, M. W. & Wilson, D. B. (1998). Effective intervention for serious juvenile offenders: A synthesis of research. In D. P. Farrington (Ed.), Serious & violent juvenile offenders: Risk factors and successful interventions (pp. 313–345). Thousand Oaks, CA: Sage.

    Google Scholar 

  • Lipsey, M. W. & Wilson, D. B. (2001). Practical meta-analysis. Thousand Oaks: Sage.

    Google Scholar 

  • Lösel, F. (1995). The efficacy of correctional treatment: A review and synthesis of meta-evaluations. In J. McGuire (Ed.), What works: Reducing reoffending. Guidelines from Practice and Research (pp. 79–111). Chichester, UK: Wiley.

    Google Scholar 

  • Lösel, F. (2000). The efficacy of sexual offender treatment: A brief review of German and international evaluations. In P. J. van Koppen & N. Roos (Eds.), Rationality, information and progress in law and psychology. In honour of Hans Crombag (pp. 145–170). Maastricht, NL: Metajuridica Publications.

    Google Scholar 

  • Lösel, F. (2001a). Rehabilitation of the offender. In P. B. Baltes (Ed.), International encyclopedia of the social & behavioral sciences (Vol. 19, pp. 12988–12993). Amsterdam: Elsevier.

    Google Scholar 

  • Lösel, F. (2001b). Evaluating the effectiveness of correctional programs: Bridging the gap between research and practice. In G. A. Bernfeld, D. P. Farrington & A. W. Leschied (Eds.), Offender rehabilitation in practice. Implementing and evaluating effective programs (pp. 67–92). Chichester, UK: Wiley.

    Google Scholar 

  • Lösel, F. & Beelmann, A. (2003). Effects of child skills training in preventing antisocial behavior: A systematic review of randomized evaluations. Annals of the American Academy of Political and Social Science 587, 84–109.

    Google Scholar 

  • Lösel, F. & Köferl, P. (1989). Evaluation research on correctional treatment in West Germany: A meta-analysis. In H. Wegener, F. Lösel & J. Haisch (Eds.), Criminal behavior and the justice system (pp. 334–355). New York: Springer.

    Google Scholar 

  • Lösel, F. & Schmucker, M. (2003). The efficacy of sex offender treatment: A brief synthesis of meta-analyses. Report for the Campbell Crime and Justice Group (Updated). University of Erlangen–Nuremberg: Institute of Psychology.

  • Lösel, F. & Wittmann, W. W. (1989). The relationship of treatment integrity and intensity to outcome criteria. New Directions for Program Evaluation 42, 97–108.

    Google Scholar 

  • Marques, J. K., Wiederanders, M., Day, D. M., Nelson, C. & von Ommeren, A. (2004). Effects of a relapse prevention program on sexual recidivism: Final results from California’s Sex Offender Treatment and Evaluation Project (SOTEP). Unpublished manuscript. Sacramento, CA: California Department of Mental Health.

    Google Scholar 

  • Marshall, W. L. & McGuire, J. (2003). Effect sizes in the treatment of sexual offenders. International Journal of Offender Therapy and Comparative Criminology 47, 653–663.

    Google Scholar 

  • McGuire, J. (2002). Integrating findings from research reviews. In J. McGuire (Ed.), Offender rehabilitation and treatment: Effective programmes and policies to reduce re-offending (pp. 3–38). Chichester, UK: Wiley.

    Google Scholar 

  • McMurran, M. (Ed.). (2002). Motivating offenders to change: A guide to enhancing engagement in therapy. Chichester, UK: Wiley.

  • Overton, R. C. (1998). A comparison of fixed-effects and mixed (random-effects) models for meta-analysis tests of moderator variable effects. Psychological Methods 3, 354–379.

    Google Scholar 

  • Polizzi, D. M., MacKenzie, D. L. & Hickman, L. J. (1999). What works in adult sex offender treatment? A review of prison- and non-prison-based treatment programs. International Journal of Offender Therapy and Comparative Criminology 43, 357–374.

    Google Scholar 

  • Prentky, R. A., Lee, A. F. S., Knight, R. A. & Cerce, D. (1997). Recidivism rates among child molesters and rapists: A methodological analysis. Law and Human Behavior 21, 635–659.

    Google Scholar 

  • Quinsey, V. L., Harris, G. T., Rice, M. E. & Lalumière, M. L. (1993). Assessing treatment efficacy in outcome studies of sex offenders. Journal of Interpersonal Violence 8, 512–523.

    Google Scholar 

  • Rice, M. E. & Harris, G. T. (2003). The size and sign of treatment effects in sex offender therapy. In R. A. Prentky, E. S. Janus & M. C. Seto (Eds.). Sexually coercive behavior: Understanding and management (pp. 428–440). New York: New York Academy of Sciences.

    Google Scholar 

  • Rösler, A. & Witztum, E. (2000). Pharmacotherapy of paraphilias in the next millennium. Behavioral Sciences and the Law 18, 43–56.

    Google Scholar 

  • Ruddijs, F. & Timmerman, H. (2000). The Stichting ambulante preventie projecten method: A comparative study of recidivism in first offenders in a Dutch outpatient setting. International Journal of Offender Therapy and Comparative Criminology 44, 725–739.

    Google Scholar 

  • Shadish, W. R., Cook, T. D. & Campbell, D. T. (2002). Experimental and quasi-experimental designs for generalized causal inference. Boston, MA: Houghton Mifflin.

    Google Scholar 

  • Sherman, L., Gottfredson, D., MacKenzie, D., Eck, J., Reuter, P. & Bushway, S. (1997). Preventing crime: What works, what doesn’t, what’s promising. Report to the U.S. Congress, Washington, DC.

  • Weisburd, D., Petrosino, A. & Mason, G. (1993). Design sensitivity in criminal justice experiments. In M. Tonry (Ed.), Crime and justice (Vol. 17, pp. 337–379). Chicago: University of Chicago Press.

  • Weisburd, D., Lum, C. M. & Petrosino, A. (2001). Does research design affect study outcomes in criminal justice? Annals of the American Academy of Political and Social Science 578, 50–70.

    Google Scholar 

  • Weisburd, D., Lum, C. M. & Yang, S.-M. (2003). When can we conclude that treatments or programs “don’t work”? Annals of the American Academy of Political and Social Science 587, 31–48.

    Google Scholar 

  • White, P., Bradley, C., Ferriter, M. & Hatzipetrou, L. (1998). Managements for people with disorders of sexual preference and for convicted sexual offenders. The Cochrane Database of Systematic Reviews. (1998, Issue 4).

  • Wille, R. & Beier, K. M. (1989). Castration in Germany. Annals of Sex Research 2, 103–133.

    Google Scholar 

  • Wilson, D. B. (2001). Meta-analytic methods for criminology. Annals of the American Academy of Political and Social Science 578, 71–89.

    Google Scholar 

  • Worling, J. R. & Curwen, T. (2000). Adolescent sexual offender recidivism: Success of specialized treatment and implications for risk prediction. Child Abuse & Neglect 24, 965–982.

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. University of Erlangen, Nuremberg, Germany

    Friedrich Lösel & Martin Schmucker

  2. Institute of Psychology, Bismarckstr. 1, 91054, Erlangen, Germany

    Martin Schmucker

Authors
  1. Friedrich Lösel
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Martin Schmucker
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Martin Schmucker.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Lösel, F., Schmucker, M. The effectiveness of treatment for sexual offenders: A comprehensive meta-analysis. J Exp Criminol 1, 117–146 (2005). https://doi.org/10.1007/s11292-004-6466-7

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11292-004-6466-7

Keywords

  • Psychosocial Intervention
  • Sexual Offender
  • Outcome Difference
  • Organic Treatment
  • Program Completion