The effects of sexual offender treatment on recidivism: an international meta-analysis of sound quality evaluations

Abstract

Objectives: Sound evaluations of sexual offender treatment are essential for an evidence-based crime policy. However, previous reviews substantially varied in their mean effects and were often based on methodologically weak primary studies. Therefore, the present study contains an update of our meta-analysis in the first issue of this journal (Lösel and Schmucker Journal of Experimental Criminology, 1, 117–146, 2005). It includes more recent primary research and is restricted to comparisons with equivalent treatment and control groups and official measures of recidivism as outcome criteria. Methods: Applying a detailed search procedure which yielded more than 3000 published and unpublished documents, we identified 29 eligible comparisons containing a total of 4,939 treated and 5,448 untreated sexual offenders. The study effects were integrated using a random effects model and further analyzed with regard to treatment, offender, and methodological characteristics to identify moderator variables. Results: All eligible comparisons evaluated psychosocial treatment (mainly cognitive behavioral programs). None of the comparisons evaluating organic treatments fulfilled the eligibility criteria. The mean effect size for sexual recidivism was smaller than in our previous meta-analysis but still statistically significant (OR = 1.41, p