Sexual Abuse: A Journal of Research and Treatment 22(4) 443–470 © The Author(s) 2010 Reprints and permission: http://www. sagepub.com/journalsPermissions.nav DOI: 10.1177/1079063210384274 http://sajrt.sagepub.com XXX10.1177/1079063210384274Barnett et al.Sexual Abuse 1 National Offender Management Service, London Corresponding Author: Georgia D. Barnett, Rehabilitation Services Group, Room 130 Abell House, John Islip Street, London, SW1P 4LH Email: georgia.barnett@noms.gsi.gov.uk An Examination of the Predictive Validity of the Risk Matrix 2000 in England and Wales Georgia D. Barnett 1 , Helen C. Wakeling 1 , and Philip D. Howard 1 Abstract This study examined the predictive validity of an actuarial risk-assessment tool with convicted sexual offenders in England and Wales. A modified version of the RM2000/s scale and the RM2000 v and c scales (Thornton et al., 2003) were examined for accuracy in predicting proven sexual violent, nonsexual violent, and combined sexual and/or nonsexual violent reoffending in a sample of sexual offenders who had either started a community sentence or been released from prison into the community by March 2007. Rates of proven reoffending were examined at 2 years for the majority of the sample (n = 4,946), and 4 years (n = 578) for those for whom these data were available. The predictive validity of the RM2000 scales was also explored for different subgroups of sexual offenders to assess the robustness of the tool. Both the modified RM2000/s and the complete v and c scales effectively classified offenders into distinct risk categories that differed significantly in rates of proven sexual and/or nonsexual violent reoffending. Survival analyses on the RM2000/s and v scales (N = 9,284) indicated that the higher risk groups offended more quickly and at a higher rate than lower risk groups. The relative predictive validity of the RM2000/s, v, and c, as calculated using Receiver Operating Characteristics (ROC) analyses, were moderate (.68) for RM2000/s and large for both the RM2000/c (.73) and RM2000/v (.80), at the 2-year follow-up. RM2000/s was moderately accurate in predicting relative risk of proven sexual reoffending for a variety of subgroups of sexual offenders. Keywords sexual offender, actuarial risk assessment, Risk Matrix 2000 Article at PENNSYLVANIA STATE UNIV on May 13, 2016 sax.sagepub.com Downloaded from