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Prospective dynamic assessment of risk of sexual reoffending in individuals with intellectual disability and a history of sexual offending behaviour. Rachael Lofthouse, School of Psychology, Bangor University, UK William R. Lindsay, Castlebeck, Darlington, UK and Bangor University, UK Vasiliki Totsika, School of Psychology, Bangor University, UK Richard P. Hastings, School of Psychology, Bangor University, UK Douglas P. Boer, The University of Waikato, New Zealand James L. Haavan, Oregon, Portland, USA Forensic risk assessment 1. Unstructured clinical opinion Low levels of reliability & accuracy (Monahan, 1981) 2. Actuarial assessment Fixed variables – e.g. number of previous offences Effective in long term prediction (Hanson & Brussiere, 1998; Quinsey et al., 2004) Initial work in ID – apply mainstream tools to ID offenders (Quinsey et al., 2004; Lindsay et al., 2008) Static assessments with ID • Actuarial assessments show promising results with ID (Lindsay et al., 2008), but effect sizes are moderate (Lindsay & Beail, 2004) • Opinions divided regarding use of actuarial assessments with ID • Some risk factors are less important for ID (Lindsay et al., 2004a) • Criticism: Don’t recognise variability in risk. Fail to measure response to treatment (Hudson et al., 2002) Dynamic risk assessment • Subdivided into Stable & Acute (Hanson & Harris, 2000) Stable: endure e.g. attitude Acute – rapidly changing e.g. access to intoxicants (Lindsay et al., 2004b) • Violent behaviour: dynamic ID tools lead to good prediction (e.g. DRAMS, Lindsay et al., 2004b; Steptoe et al., 2008) • Dynamic variables better at predicting risk of sexual reoffending (Lindsay et al., 2004a) • ARMIDILO-S (Boer et al., 2004): predicts sexual recidivism for ID offenders more accurately than static measures (Courtney, 2008; Blacker et al., 2010). Current research project Research aims Add to the evidence for predictive accuracy of ARMIDILO-S. 1. Environmental & offender factors 2. Prospective design 3. All items 4. IQ scores Method Participants 64 males with ID & history of SO. Average age 32.8 years (17-63), IQ 67 (54-75) Community ID service, Scotland, UK Measures – baseline 2003 ARMIDILO-S (Boer et al., 2004) 30 items: divided into stable & acute; environment & offender. 3 scores obtained: environment, offender & total score. Measures cont..... Actuarial assessments from file review: • Static -99 (Hanson & Thornton, 2000) • VRAG (Quinsey et al., 1998) 2009 Outcome variable: ‘Sexual recidivism’ Any behaviour with a sexual motive including contact & none contact offences, official & unofficial reports. Predictive accuracy: Receiver Operator Characteristic (ROC) Area Under Curve (AUC) Results ARMIDILO-S sub-scale ROC AUC scores Stable environment .79, p<.000 Acute environment .77, p<.000 Environmental score .81, p<.001 Stable offender .88, p<.000 Acute offender .67, p<.029 Offender score .90, p<.001 ARMIDILO total score .92, p<.001 Figure 1 Characteristics of the receiver operating characteristic (ROC curve for ARMIDILO-S (total score, offender subscale score and staff & environment subscale score) Static-99 (AUC=.74, p=.002) VRAG (AUC=.58, p=.33) Figure 2 Characteristics of the receiver operating characteristic (ROC) curve for Static-99 & VRAG Analysis for IQ < 70 (n=42) Risk Assessment ROC AUC ARMIDILO-S environment .79, p = .003 subscale ARMIDILO-S Offender .85, p < .001 subscale ARMIDILO-S Total subscale .90, p < .001 Static-99 .74, p = .010 VRAG .56, p = .555 Discussion • Dynamic nature of ARMIDILO-S accounts for efficacy based on Static - 99 performance and previous studies (Lindsay et al., 2008) • Consistent with previous research: dynamic items outperformed static (Lindsay et al., 2004a) • Large effect sizes support notion to consider individuals & environment separately (Boer et al., 2004) • Static measures useful with ID if relevant to outcome Discussion & Limitations • Dynamic assessments = responsive risk assessments Limitations • RRASOR not included (Boer et al., 2004) Conclusion • Dynamic tools of value with ID offenders • Dynamic tools address some limitations of actuarial tools • ARMIDILO-S worthy of further validation Thank you for listening Contact details: email@example.com References Blacker J., Beech A.R., Wilcox D.T & Boer D.P. (2010) The assessment of dynamic risk and recidivism in a sample of special needs sexual offenders. Psychology, Crime and Law. Boer G.P., Tough S. & Haaven J. (2004) Assessment of risk manageability of intellectual disabled sex offenders. Journal of Applied Research in Intellectual Disabilities, 17, 275-283. Boer D.P., McVilly K.R. & Lambick F. (2007) Contextualising risk in the Assessment of Intellectually Disabled Individuals. Sexual Offender Treatment 2(2) Courtney J. (2008) The identification of Recidivism Indicators in Intellectually Disabled Violent Individuals. Unpublished MSc thesis, The University of Waikato, New Zealand Hanson R.K. & Bussiѐre M.T. (1998) Predicting relapse: A meta-analysis of sexual offender recidivism studies. Journal of Consulting and Clinical Psychology, 66, 348-362. Hanson R.K & Harris A.J.R. (2000) Where should we intervene? Dynamic predictors of sexual offense recidivism. Criminal Justice and Behaviour, 27, 6-35 Hanson R.K. & Thornton D. (2000). Improving risk assessments for sex offenders: A comparison of three actuarial scales. Law and human behaviour, 24, 119-136 Lindsay W.R. & Beail N. (2004) Risk assessment: actuarial prediction and clinical judgement of offending incidents and behaviour for intellectual disability services. Journal of Applied Research in Intellectual Disabilities, 17, 229-234. Lindsay W.R., Elliot S.F. & Astell A. (2004a) Predictors of sexual offence recidivism in offenders with learning disabilities. Journal of Applied Research in Intellectual Disabilities, 17, 299-305. Lindsay W. R., Hogue T. E., Taylor J. L., Steptoe L., Mooney P., O'Brien G. et al. (2008) Risk assessment in offenders with intellectual disability: A comparison across three levels of security. International Journal of Offender Therapy & Comparative Criminology, 52, 90-111. Lindsay W.R., Murphy L., Smith G., Murphy D., Edwards Z., Chittock C. et al. (2004b) The Dynamic Risk Assessment and Management System: An Assessment of Immediate Risk of Violence for Individuals with Offending and Challenging Behaviour. Journal of Applied Research in Intellectual Disabilities, 17, 267-274 Quinsey V.L., Book A.B. & Skilling T.A. (2004) A Follow-up of Deinstitutionalized Men with Intellectual Disabilities and Histories of Antisocial Behaviour. Journal of Applied Research in Intellectual Disabilities 17, 243-253 Quinsey V.L., Harris G.T., Rice M.E. & Cormier C.A. (1998) Violent Offenders: Appraising and Managing Risk. Washington DC: America Psychological Association ARMIDILO-S items Stable dynamic environmental: attitudes towards ID sex offenders, communication amongst supervisory staff to ensure information sharing, client specific knowledge by staff, consistency of supervision, environmental consistency including the physical setting and relationships. Acute dynamic environmental: changes in social relationships, supervisory staff, monitoring by staff, victim access, and environmental changes such as relocation. Changes in victim access, access to intoxicants. Stable dynamic offender items: attitudes and compliance with supervision and treatment, knowledge of cognitive distortions, crime cycle, risk factors and relapse prevention plan, sexual knowledge and self management of sexuality, mental health, monitoring ability and self management, time management skills and planning ability, substance abuse, victim selection and acquisition/grooming behaviour, general coping ability and self efficacy, relationship and ‘relating to others’ skills, threat or use of violence against self or others, impulsiveness and offender specific stable dynamic factors, which are potentially numerous but can include family related problems for example. Acute dynamic offender: changes in social support or significant relationships, changes to substance abuse pattern, changes in sexual preoccupation, changes in victim access or preoccupation with victim selection and acquisition or grooming of victim, changes in attitude or behaviour towards supervision or treatment, changes in ability to use coping strategies or recognise risky situations or failure to use problem solving strategies, changes to routine and offender specific acute dynamic variables; again there are numerous possibilities specific to the individual. DRAMS Lindsay et al. (2004b) - found a relationship between mood, anti social behaviour and total DRAMS score the day before an aggressive incident. Steptoe et al. (2008) - mood (AUC=.74), anti-social behaviour (AUC=.70) and intolerance/agreeableness (AUC=.71) 1- 2 days before incidents of violent behaviour were predictive of a violent incident. Blacker 2010 IQ<75 (n=10) analysed separately For this group the ARMIDILLO - Stable scale produced a significant predictive effect (AUC=.86) as did the ARMIDILLO acute (AUC=.75). The actuarial measures performed little better than chance level at distinguishing sexual recidivists from non recidivists.
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