Risk Assessment for Future Violence in Individuals from an Ethnic Minority Group

Abstract

Across several countries (including the UK and U.S.) people of black (African-Caribbean) origin are overrepresented in secure psychiatric services. Risk assessment instruments for predicting violence are often used, but their accuracy is not known for ethnic minority patients. We therefore aimed: 1) to test the accuracy of two leading instruments (Violence Risk Appraisal Guide (VRAG) and HCR20 Risk Management Scheme) in patients from a black ethnic minority, and (2) to compare the levels of risk as defined by these instruments. Risk assessments were completed using only file information available at the time of discharge. Offending behavior postdischarge was obtained from official records with each patient being followed for at least 2 years. Both VRAG and HCR-20 were significant predictors of future violence for black patients, and had similar accuracy as when used on white patients. Risk assessment scores were slightly lower for black patients, but there were no significant differences in reconviction rates for either violent or general offences post discharge. The results provide an evidence base for the use of HCR-20 and VRAG as an accurate risk assessment instruments for black ethnic minority patients in the UK.

Keywords:

• Violence risk assessment
• VRAG
• HCR-20
• ethnic minorities

This work was funded by a grant from Partnerships in Care. We thank the UK Ministry of Justice for providing us with information concerning criminal convictions in our cohort of mentally disordered offenders.

Notes

¹Though the vast majority of this research merely used the number of risk factors present to make the risk prediction rather than a true clinical judgment.

²Whilst the white and black groups were reasonably matched for gender there is still the possibility that this might have influenced the results, particularly so given some evidence for rather poorer validity for such instruments in female samples (see Garcia-Mansilla, Rosenfeld and Nicholls, 2009). A supplementary analysis using only the male patients showed a similar pattern to that reported, namely HCR-20 AUC (SE) was 0.73 (0.03) for the white group and 0.68 (0.06) for the black group. For the VRAG the AUCs were 0.83 (0.03) for the white group and 0.75 (0.07) for the black group.

³Due to collection of VRAG data starting later, and the different rules that govern whether the assessment can be completed for each instrument, the AUCs for the VRAG and HCR20 are based on largely overlapping, but not identical samples. In a supplementary analysis we analysed only those patients where we had been able to complete both instruments. The results were nearly identical to those reported in the main text. For the white group (n = 380) the AUC (SE) for the HCR-20 = 0.73 (0.04) and VRAG = 0.78 (0.03). For the black group (n = 120) HCR-20 = 0.68 (0.07) and VRAG = 0.74 (0.07).

⁴Of course a person with a strong racial bias might deliberately ignore or distort information, hence no assessment is truly bias free.