Better than clairvoyance? Exploratory results on predictors of regular release, substance use and re-delinquency after forensic addiction treatment.

Forensic addiction treatment (FAT) aims to reduce the risk of offences originating in substance use. Hence, reoffending is a key outcome criterion besides therapy completion and substance use. Previous research on success prognoses resulted in heterogeneous sets of predictors. This is the first study to exploratorily investigate three types of predictors and to compare their predictive values on three outcome criteria by using a coherent, multi-centric database. Data from 4,201 patients released from German FAT were used, testing 182 variables. Stepwise logistic regression analyses were computed. Resulting predictor sets were widely heterogeneous. While regular release could satisfactorily be predicted by historical variables only, variance explanation was much lower for substance use and re-delinquency. Including treatment-related and post-treatment variables raised variance explanation up to R2 = .46 (p < .001). Success should be seen as a dynamic process that is strongly influenced by alterable variables taking effect during and after FAT.