1. The document reviews 5 studies that examine the predictive validity of commonly used risk assessment instruments for intellectually disabled sex offenders. 2. Several instruments, including the VRAG, PCL:SV, HCR-20, Static-99, and RM 2000, showed sufficient or good predictive validity in assessing risks of sexual and general recidivism according to the studies. 3. However, more research is still needed to evaluate the predictive validity of instruments for assessing risk of sexual recidivism after treatment.

1. Risk Assessment with Intellectually Disabled Sex Offenders
Jan Willem van den Berg & Daan van Beek
Van der Hoeven Kliniek
Utrecht, The Netherlands
RESULTSRESULTS
Study N IQ Follow-up
period
Instruments Interrater
reliability
Type recidivisme in AUC-value
Sexual Violent General
Quinsey
e.a. (2004)
58 IQ< 70 Average 16
months after
release
VRAG .69*
Gray e.a.
(2007)
1141 N=145
IQ<70
Between 2
and 5 years
after release
VRAG .73* .74*
PCL:SV .73* .76*
HCR-20 .79* .81*
Lindsay
e.a. (2008)
212 Mean IQ
between
64,7 –
66,7
During 12
months of
treatment
VRAG 92%a
.71**
HCR-20 .72**
Static-99 97%a
.71**
RM 2000 V 91%a
.62
RM 2000 S 92%a
.61
Wilcox e.a.
(2009)
27 IQ<80 76 months Static-99 .64
RM 2000 .58
RRASOR .42
Verbal
violence or
violence
against
property
Physical violence
Morrissey
e.a. (2007)
60 Mean IQ
66,2
During 12
months of
treatment
PCL-R .80b
.49 .54
HCR-20 .77* .68*
Notes:
* p < .05
** p < .01
a The interrater reliability is based on 30 cases whom where rated by 2 independent professionals. A percentage of 92% means that both professionals have the same judgment in 92% of the
cases.
b The interrater reliability depends on an unmentioned number of cases.
Research into risk factors for sexual
offending increased tremendously over
the past decades. At the same time risk
assessment instruments have become
highly influential within the field of
forensic psychiatry. Nevertheless, little is
known about the predictive validity of
these instruments with intellectually
disabled sex offenders (Boer, Though &
Haaven, 2004).
The aim of this study is to ascertain which
instruments can provide a sufficient or
good prediction of (sexual) recidivism in
intellectual disabled forensic psychiatric
patients.
AIM OF THIS STUDYAIM OF THIS STUDY
With Pubmed, PsycINFO and Scholar
Google a search is done for studies
published between 1980 and 2010 on the
predictive validity of risk assessment
instruments used for assessing forensic
psychiatric patients with an intellectual
disability. Words such as ‘mental
retardation’, ‘mental disability’,
‘intellectual disability’, ‘learning disorder’,
‘risk assessment’ and equivalents were
used in different combinations. For this
poster we selected the five articles that
deal with forensic risk assessment of
intellectually disabled offenders which
presented AUC-values.
METHODMETHOD
CONTACTINFORMATIONCONTACTINFORMATION
E-mail: jwvandenberg@hoevenkliniek.nl
More information on:
www.linkedin.com/in/janwillemvandenberg
CONCLUSIONSCONCLUSIONS
REFERENCESREFERENCES
Boer, D.P., Tough, S., & Haaven, J. (2004). Assessment of risk
manageability of intellectually disabled sex offenders. Journal of
Applied Research in Intellectual Disabilities, 17, 275-283.
Gray, N.S., Fitzgerald, S., Taylor, J., MacCullloch, M.J., &
Snowden, R.J. (2007). Predicting future reconviction in offenders
with intellectual disabilities: The predictive efficacy of VRAG,
PCL:SV and the HCR-20. Psychological Assessment, 19, 474-479.
Lindsay, W.L., Hogue, T.E., Taylor, J.L., Steptoe, L., Mooney,
P., O’Brien, G., Johnston, S., & Smith, A.H.W. (2008). Risk
assessment in offenders with intellectual disability. A comparison
across three levels of security. International Journal of Offender
Therapy and Comparative Criminology, 52, 90-111.
Morrissey, C., Hogue, T., Mooney, P., Allen, C., Johnston, S.,
Hollin, C., Lindsay, W.R., & Taylor, J.L. (2007). Predictive validity of
the PCL-R in offenders with intellectual disability in a high secure
hospital setting: Institutional aggression. The Journal of Forensic
Psychiatry & Psychology, 18, 1-15.
Quinsey, V.L., Book, A., & 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.
Wilcox, D., Beech, A., Markall, H.F., & Blacker, J. (2009).
Actuarial risk assessment and recidivism in a sample of UK
intellectually disabled sexual offenders. Journal of Sexual
Aggression, 15, 97-106.
1.Several commonly used risk assessment
instruments appear to have sufficient or
good predictive validity.
2.Two studies found a good interrater
reliability of the instrument which were the
object of research (VRAG, Static-99, RM
2000 and PCL-R).
3.The VRAG, PCL:SV and HCR-20 can be
used in assessing general and violent risk.
4.There is some evidence that the Static-
99 and HCR-20 can be used for assessing
risk of sexual offence during treatment.
5.More research has to take place
especially on the predictive validity of risk
assessment instruments for assessing
risk of sexual recidivism after treatment.