Actuarial Risk Assessment of Sexual Offenders: The Psychometric Properties of the Sex Offender Risk Appraisal Guide (SORAG)

The Sex Offender Risk Appraisal Guide (SORAG) is one of the most commonly used actuarial risk assessment instruments for sexual offenders. The aims of the present field study were to examine the predictive validity of the German version of the SORAG and its individual items for different offender subgroups and recidivism criteria in sexual offenders released from the Austrian Prison System (N = 1,104; average follow-up period M = 6.48 years) within a prospective-longitudinal research design. For the prediction of violent recidivism the German version of the SORAG yielded an effect size of AUC =.74 (p < .001, 95% CI =.70 -. 78). The predictive accuracy for general and violent recidivism was slightly higher than for general sexual and sexual hands-on recidivism. The effect sizes were found to be higher for the child molester sample than for rapists. However, the differences were significant only for general recidivism (z = 2.48, p =.001). Further analyses exhibited the SORAG to have incremental predictive validity beyond the VRAG and the PCL-R, and to remain the only significant predictor for violent recidivism once all 3 instruments were forced into a combined regression model. Twelve out of the 14 SORAG items were found to have a significant positive relationship with violent recidivism. The comparison of the relative and absolute risk indices between the Austrian and the Canadian samples showed that the normative data distribution yielded more (absolute risk indices) or less (relative risk indices) meaningful differences between the 2 countries.