Introduction: The "Dunkelfeld" project offers pharmacologic treatment and psychotherapy to self-referred pedophilic patients in an anonymous way.
Aim: To provide a re-assessment focusing on the crucial time × group interaction (ie, the treatment effect).
Methods: A recent study reported on the effectiveness of the "Dunkelfeld" program based on intermediate data of a treatment group (TG; n = 53) and a waiting-list control group (CG; n = 22). With psychological indicators, it was concluded that the therapy program changed dynamic risk factors that are associated with sexually offending against children. Although based on an independent groups pre-post design, the original report includes within-group pre- and post-comparisons only, as well as between-group comparisons at the pre- and post-treatment stages. In the current study, an effect size index was computed that compares the change occurring in both groups (TG and CG) with each other (Morris d). Moreover, 95% CI of d were calculated.
Main outcome measures: The analyses were limited to 12 dynamic risk factors pertaining to emotional dysfunction, offense-supportive attitudes, sexual dysregulation, impression management, and 2 types of delinquent behavior, including recent behavior related to sexual offenses against children and recent use of child sexual abuse images.
Results: All 14 indicators showed weak treatment effects at most, with a median d of 0.30. None of the effect sizes was statistically significant (ie, in every case the 95% CI included 0). Further methodologic concerns include a familywise error rate close to 1 and too little statistical power to identify potential effects.
Clinical implications: As far as dynamic risk factors are concerned, the data do not show that treatment within the "Dunkelfeld" program leads to any reduction of the proneness to commit sexual offenses against children.
Strengths & limitations: The current study adds crucial information lacking in the original analysis. Because the re-appraisal has the same limited statistical power as the original study, the current results are tentative in the sense that the possibility of the program being effective cannot be ruled out. A further limitation is that not all of the dynamic risk factors chosen as indicators of possible treatment success have been established as relevant for sexual (re-)offending in prior empirical studies.
Conclusions: The outcome emphasizes the notion that independent groups pretest-posttest designs should be analyzed based on the treatment × time interaction. Mokros A, Banse R. The "Dunkelfeld" Project for Self-Identified Pedophiles: A Reappraisal of its Effectiveness. J Sex Med 2019;16:609-613.
Keywords: Effect Size; Independent Groups Pretest-Posttest Design; Morris d; Pedophilia; Sexual Offenses Against Children.
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