Predicting institutional violence in offenders with intellectual disabilities: the predictive efficacy of the VRAG and the HCR-20.

BACKGROUND: There is a developing evidence base to support the use of risk assessment instruments in offenders with intellectual disability (ID). The aim of this study was to try to develop this literature with the inclusion of a control group of mentally disordered offenders without an ID, using the HCR-20 and VRAG. MATERIALS AND METHODS: The VRAG and the HCR-20 were completed for a group of offenders with an ID (n = 25) and a control group (n = 45), in four medium-secure units across the UK. The outcome measure was physical aggression measured over 6 months. RESULTS: Both instruments consistently produced large effect sizes predicting any physical aggression and severe physical aggression. The structured clinical judgement based on the HCR-20 was especially good. CONCLUSIONS: The HCR-20 and the VRAG have excellent predictive efficacy in offenders with an ID. A structured clinical judgement based on the HCR-20 was especially predictive.

Predicting future reconviction in offenders with intellectual disabilities: the predictive efficacy of VRAG, PCL-SV, and the HCR-20.

Accurate predictions of future reconviction, including those for violent crimes, have been shown to be greatly aided by the use of formal risk assessment instruments. However, it is unclear as to whether these instruments would also be predictive in a sample of offenders with intellectual disabilities. In this study, the authors have shown that the Violence Risk Appraisal Guide (V. L. Quinsey, G. T. Harris, M. E. Rice, & C. Cormier, 1998); the Psychopathy Checklist--Screening Version (S. D. Hart, D. N. Cox, & R. D. Hare, 1995); and the History, Clinical, Risk Management--20 (C. D. Webster, K. S. Douglas, D. Eaves, & S. D. Hart, 1997) were all significant predictors of violent and general reconviction in this sample, and in many cases, their efficacy was greater than in a control sample of mentally disordered offenders without an intellectual disability.

Assessing risk of future violence among forensic psychiatric inpatients with the Classification of Violence Risk (COVR).

OBJECTIVES: Instruments are needed to help clinicians make decisions about a patient's risk of future violence in order to manage this risk, protect others, and allocate resources. One such actuarial instrument-the Classification of Violence Risk (COVR)-was developed from the MacArthur Violence Risk Assessment Study. The COVR has not been validated in a sample other than the one with which it was constructed or outside of the United States. The purpose of this study was to provide an independent validation of the COVR in a sample of forensic psychiatric inpatients in the United Kingdom. METHODS: The prospective study was conducted at four medium-security forensic psychiatric units over six months. Two risk assessment instruments were completed for 52 patients: the COVR and the Violence Risk Appraisal Guide (VRAG), a well-established actuarial instrument. Incidents of verbal aggression, physical aggression toward others, and aggression against property were documented for the next six months from nursing records. Predictive accuracy of the instruments was analyzed using both correlational techniques and signal detection theory. RESULTS: COVR was a good predictor of both verbal and physical aggression. Its predictive ability was similar to that of the VRAG, although the VRAG was a better predictor of violence to property. CONCLUSIONS: The study provides the first independent validation of the COVR and evidence of the usefulness of the COVR in predicting harmful behavior in forensic inpatient settings in the United Kingdom.