On the Effectiveness of Sexual Offender Treatment in Prisons: A Comparison of Two Different Evaluation Designs in Routine Practice

Abstract

Although there is less continuity of sexual offending in the life course than stereotypes suggest, treatment should lead to a further reduction of reoffending. Contrary to this aim, a recent large British study using propensity score matching (PSM) showed some negative effects of the core sex offender treatment program (SOTP) in prisons. International meta-analyses on the effects of sex offender treatment revealed that there is considerable variety in the results, and methodological aspects and the context play a significant role. Therefore, this study compared different designs in the evaluation of sex offender treatment in German prisons. PSM was compared with an exact matching (EM) by the Static-99 in a sample of 693 sex offenders from Bavarian prisons. Most results were similar for both methods and not significant due to low base rates. There was a treatment effect at p < .05 on general recidivism in the EM and at p = .06 on serious reoffending in the PSM. For sexual recidivism, EM showed a negative trend, whereas PSM suggested the opposite. Overall, the study underlines the need for more replications of evaluations of routine practice, methodological comparisons, sensitive outcome criteria, and differentiated policy information.

“Mixed” Sexual Offending Against Both Children and Adults: An Empirical Comparison With Individuals Who Exclusively Offended Against Child or Adult Victims

“…Time at risk (in months) was defined as the time between an individual's release from prison and the day the recidivism data were retrieved. Treatment status was coded dichotomously with 0 = no sex offense specific treatment and 1 = any sex offense specific treatment (individual therapy/group therapy/social therapy; see Lösel et al, 2020). The Sex Offender Questionnaire included all items of the Static-99 (Hanson & Thornton, 1999), a 10-item actuarial risk assessment instrument for individuals who sexually offended, and sum scores were calculated as an indicator for each participant's static risk for reoffending.…”

“…Although there are overall encouraging results on treatment effectiveness (Schmucker & Lösel, 2015, treatment in prison settings is still discussed controversially, and some large studies even suggest unintended negative effects, that is, more reoffending in treated than in control groups (e.g., Mews et al, 2017). This can be due to various methodological, context, and treatment factors (e.g., Lösel et al, 2020), but individual characteristics may also play an important role.…”

Entwicklungspfade der Straftäterbehandlung: skizzierte Wege und Evaluation der Zielerreichung

“…In Evaluationen zeigten TC u. a. Erfolge bei persönlichkeitsgestörten, gewalttätigen oder substanzabhängigen Straftätern (Aos et al 2001;Holloway et al 2008;Lösel 1995;Lipton et al 2002), wobei zumeist auch spezifischere Programme wie CBT eingebunden waren. Was die deutschen SothA betrifft, gibt es ermutigende Ergebnisse bei der allgemeinen Rückfälligkeit und psychischen Merkmalen; beim sexuellen Rückfall sind die Ergebnisse bislang weniger überzeugend (Endres 2014;Lösel et al 2019;Schwedler und Wößner 2013).…”

Special Issue: International Developmental/Life-Course Perspectives and Research on Sexual Offending and Offenders

“…As the first four articles in the special issue focused on DLC-informed risk factors for predicting recidivism (Ozkan et al, 2020), early onset offending (Rosa et al, 2020), and offending trajectories (Reale et al, 2020; Spaan et al, 2020), the fifth article in the special issue authored by Lösel and colleagues (2020) offered an evaluation of the effectiveness of in-prison treatment for persons with sexual offense histories in Germany. Lösel et al (2020) performed a methodologically robust propensity score matching algorithm to statistically create a matched sample of “similarly situated” persons with sexual offense histories groups (treatment group: n = 352; control group; n = 352). Results failed to identify significant treatment effects on sexual recidivism, although the propensity score matching analysis did reveal that the sexual reoffending rate and the general reoffending rate were more favorable (i.e., lower) among the treatment group.…”