A Longitudinal Outcome Evaluation of a Prison-Based Sex Offender Treatment Program

Abstract

Sex offender outcome studies continue to produce mixed results. A common critique of these studies is their lack of methodological rigor. This study attempts to address this critique by adhering to the standards established by the Collaborative Outcome Data Committee (CODC) aimed at increasing the quality and confidence in outcome studies. We examined recidivism outcomes for a sample of formerly incarcerated sex offenders who participated in a state prison-based cognitive-behavioral-skills-based treatment program. We used propensity score analysis to compare treatment participants with a matched sample of non-participants. The final sample post-matching ( n = 512) was observed for a minimum of 4 years and a maximum of 14 years. Using survival analysis, findings indicate that there were no differences in recidivism rates between treatment participants and non-participants in sexual or violent crimes. However, participants demonstrated significantly lower rates of recidivism for non-violent crimes. We discuss strengths, limitations of the study, and implications of these findings.

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

“…In both analyses, there were no significant effects of treatment in prison on the rate of sexual reoffending. This is in accordance with recent meta-analyses (Schmucker & Lösel, 2015, 2017) and several quasi-experimental primary studies (Abracen, Looman, Ferguson, Harkins, & Mailloux, 2011; Grady et al, 2017; Olver et al, 2012; Smallbone & McHugh, 2010; Smid, Kamphuis, Wever, & van Beek, 2016). Some of the latter studies had smaller samples and applied matching methods that may have impaired equivalence of TG and CG.…”

“…Some of the latter studies had smaller samples and applied matching methods that may have impaired equivalence of TG and CG. However, there were also studies with relatively large samples and sophisticated PSM methods (e.g., Grady et al, 2017) that found no significant treatment effects on sexual reoffending. Some results were nonetheless encouraging as they showed less harmful or delayed sexual reoffending of treated offenders (Olver et al, 2012).…”

“…With PSM, Rosenbaum and Rubin (1983) proposed a method that allowed matching treatment and control group members on a large number of variables via a propensity score, thereby avoiding the major problems of single variable matching. PSM has become the method of choice in various recent evaluations of sexual offender treatment (e.g., Duwe & Goldman, 2009; Grady, Edwards, & Pettus-Davis, 2017; Mews et al, 2017), whereas in earlier studies, matching typically referred to a single or a few selected variables (e.g., Friendship et al, 2003; Procter, 1996; Rice, Harris, & Quinsey, 1991). This shift from single variable to PSM triggered our study.…”

Evidence comes by replication, but needs differentiation: the reproducibility issue in science and its relevance for criminology

“…As mentioned above, custodial programs had no significant effect on the rate of sexual recidivism, but various studies suggest that there may be an impact on other outcomes, such as a lower rate of nonsexual reoffending, or more delayed or less harmful sexual reoffending (e.g., Olver et al 2012;Smid et al 2016). Evaluations of sexual offender treatment often raise more questions than answers (Grady et al 2015). There are plausible theoretical, statistical, or practical explanations for the mixed pattern of results, but these should not only be provided post-hoc, but also form differentiated models of conditions under which treatment is successful.…”

A Call for Research on Sex Offender Treatment Programs

“…Although the study does not measure the therapeutic climate in the study, the residential environment speaks to the role of a therapeutic climate. The goal of the research was to establish a new set of rigorous guidelines for the evaluation of effective SOTPs, as it became common for studies and meta-analyses to use different criteria in each study, hindering the standardization of such research (Grady et al, 2015). The new guidelines for effectiveness were then used to evaluate one program to measure its effectiveness and test the applicability of the guidelines.…”