The validity of the Violence Risk Appraisal Guide (VRAG) in predicting criminal recidivism

The VRAG is an actuarial risk assessment instrument, developed in Canada as an aid to estimating the probability of reoffending by mentally ill offenders.

To test the predictive validity of the VRAG with a German sample.

The predictive validity of the VRAG was tested on a sample of 136 people charged with a criminal offence and under evaluation for criminal responsibility in the forensic psychiatry department at the University of Munich in 1994-95. The predicted outcome was tested by means of ROC analysis for correlation with the observed rate of recidivism between discharge after the 1994-95 assessment and the census date of 31 March 2003. Recidivism rate was calculated from the official records of the National Conviction Registry.

Just over 38% of the sample had reoffended by 2003. Their mean time-at-risk was 58 months (SD 3.391; range 0-115 months). The VRAG yielded a high predictive accuracy in the ROC analysis with an AUC of 0.703. For a constant time-at-risk < = 7 years, the predicted probability and observed rates of recidivism correlated significantly with Pearson's r = 0.941.

The validity of the VRAG was replicated with a German sample. The VRAG yielded good predictive accuracy, despite differences in sample and outcome variables compared with its original sample.