Friday, May 8, 2015

Q&A with Karl Hanson, co-author of “Less is more: Using Static-2002R Subscales to Predict Violent and General Recidivism among Sexual Offenders”

Babshishin, KM, Hanson, RK, & Blais, J. (2015). Less is more: Using Static-2002R Subscales to Predict Violent and General Recidivism among Sexual Offenders. Sexual Abuse: A Journal of Research and Treatment. Advance online publication. doi:10.1177/1079063215569544


Given that sexual offenders are more likely to reoffend with a nonsexual offense than a sexual offense, it is useful to have risk scales that predict general recidivism among sexual offenders. In the current study, we examined the extent to which two commonly used risk scales for sexual offenders (Static-99R and Static-2002R) predict violent and general recidivism, and whether it would be possible to improve predictive accuracy for these outcomes by revising their items. Based on an aggregated sample of 3,536 adult male sex offenders from Canada, the United States, and Europe (average age of 39 years), we found that a scale created from the Age at Release item and the General Criminality subscale of Static-2002R predicted nonsexual violent, any violent, and general recidivism significantly better than Static-99R or Static-2002R total scores. The convergent validity of this new scale (Brief Assessment of Recidivism Risk–2002R [BARR-2002R]) was examined in a new, independent data set of Canadian high-risk adult male sex offenders (N = 360) where it was found to be highly correlated with other risk assessment tools for general recidivism and the Psychopathy Checklist–Revised (PCL-R), as well as demonstrated similar discrimination and calibration as in the development sample. Instead of using total scores from the Static-99R or Static-2002R, we recommend that evaluators use the BARR-2002R for predicting violent and general recidivism among sex offenders, and for screening for the psychological dimension of antisocial orientation.

Could you talk us through where the idea for the research came from?

The idea for this paper arose when updating norms for the STATIC sexual offender risk assessment tools (Static-99, Static-99R, Static-2002, Static-2002R). With the original Static-99, we used the same items to predict both sexual and violent recidivism. We knew this was not optimal, but it was close. As we explored the STATIC items further, we found that certain items may be negatively related to non-sexual recidivism.  In other words, high scores on these items were related to lower rates of non-sexual violent and general recidivism (e.g., male victims). This was surprising. With the help of Robert Lehmann, we were able to quickly replicate the effect in a new data set from Germany. This gave us confidence that the effect was real.  Then, in our factor analysis work with Sébastien Brouillette-Alarie, we found that many of the items associated with non-sexual recidivism formed a clean factor.  Consequently, we thought it would be possible to improve the prediction of non-sexual recidivism by concentrating on items measuring general criminality.

What kinds of challenges did you face throughout the process?

When we started, there was a relatively small literature on the content validity of actuarial risk scales. Howard Barbaree and others had made some important contributions, but many evaluators (and more than one reviewer) seemed to have difficult thinking of criterion-referenced measures as different from norm-reference measures. We needed a framework that included both approaches. Consequently, we had to justify the conceptual frameworks as well as the specific findings.  

What kinds of things did you learn about co-authorship as a result of producing this article?

Working with great colleagues is a delight.

What do you believe to be to be the main things that you have learnt about the effectiveness of risk scales to Predict Violent and General Recidivism Among Sexual Offenders?

It is essential to understand what is being assessed by risk assessment tools, even when tools are used solely for the purpose of estimating recidivism risk.

Now that you’ve published the article, what are some implications for practitioners?

The main factors underlying sexual recidivism risk are sexual criminality, general criminality, and age.  If evaluators are interested in sexual recidivism, than all three factors should be considered.  If evaluators are interested in general or violent recidivism, then they can do better by dropping the sexual criminality items and focusing just on age and general criminality.  Less is more.


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