Reliability and Predictive Validity of the Juvenile Sex Offender Assessment Protocol-II in an Australian Context

• Author: Timea Molnar,Troy Allard,Nadine McKillop,John Rynne
• DOI: http://doi.org/10.1177/0306624X19900978
• Published date: 01 August 2022
• Date: 01 August 2022
• Subject Matter: Articles

https://doi.org/10.1177/0306624X19900978

International Journal of

Offender Therapy and

Comparative Criminology

2022, Vol. 66(10-11) 1051 –1070

© The Author(s) 2020

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DOI: 10.1177/0306624X19900978

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Article

Reliability and Predictive

Validity of the Juvenile

Sex Offender Assessment

Protocol-II in an Australian

Context

Timea Molnar1, Troy Allard1, Nadine McKillop2,

and John Rynne1

Abstract

This study investigated the reliability and predictive validity of the Juvenile Sex

Offender Assessment Protocol-II (J-SOAP-II), in an Australian context, and for

Australian Indigenous and non-Indigenous youth. Participants were 123 (n = 91 non-

Indigenous; n = 32 Indigenous) youth assessed using the J-SOAP-II and followed up

over an average period of 4 years. The reliability of the J-SOAP-II was assessed using

measures of internal consistency (Cronbach’s alphas and inter-item correlations).

Receiver operating characteristic (ROC) analyses were conducted to assess the

J-SOAP-II’s validity in predicting sexual and non-sexual (violent and non-violent)

recidivism. Overall, the J-SOAP-II demonstrated moderate to high levels of reliability

and weak to moderate levels of validity for predicting sexual and non-sexual (violent

and non-violent) recidivism for the whole sample. While the J-SOAP-II total score

was significantly associated with non-sexual (violent and non-violent) recidivism for

non-Indigenous youth, it was not significantly associated with any of the outcome

variables for Indigenous youth. Across all analyses, the dynamic scales of the J-SOAP-II

predicted recidivism with greater accuracy than the static scales. However, the static

scales had greater accuracy in predicting the risk of sexual recidivism for Indigenous

youth. While a reliable measure, these preliminary findings raise questions about

the validity of the J-SOAP-II for predicting sexual recidivism for Indigenous and non-

Indigenous youth in an Australian context, and warrant further investigation.

1Griffith University, Brisbane, Queensland, Australia

2University of the Sunshine Coast, Brisbane, Queensland, Australia

Corresponding Author:

Timea Molnar, Griffith University, 176 Messines Ridge Rd, Mount Gravatt, Brisbane, Queensland 4122,

Australia.

Email: timea.molnar@griffithuni.edu.au

900978IJOXXX10.1177/0306624X19900978International Journal of Offender Therapy and Comparative CriminologyMolnar et al.

research-article2020

1052 International Journal of Offender Therapy and Comparative Criminology 66(10-11)

Keywords

J-SOAP-II, Indigenous, youth, sexual, recidivism, reliability, predictive validity

Youth account for a large proportion of those who sexually harm. In the United States

and Canada, for example, youth under 18 years account for approximately 10% to

17% of all sexual offences reported to police (Allen, 2018; U.S. Department of

Justice, 2015). In Australia, youth account for approximately 28% of all offenders

with a principal offence of sexual assault (Australian Bureau of Statistics [ABS],

2018). Indigenous youth are further overrepresented in the proportion of youth who

sexually harm (YSH). For example, in the United States, American Indian and

Alaskan Native youth experience higher levels of involvement in the juvenile justice

system as they are two to three times more likely to be arrested for certain offences,

including sexual offences, than non-Indigenous youth (Rountree, 2015; Voisin et al.,

2017). Indigenous youth in Canada and Australia1 are also overrepresented in the

criminal justice system as they account for approximately a quarter of all sexual

offences reported to police but represent less than 5% of the population (ABS, 2017;

Hylton, 2002, 2004; Queensland Police Service, 2017; Statistics Canada, 2017).

The proportion of YSH poses a serious threat to the health and well-being of the

community (Letourneau & Borduin, 2008). For example, the annual cost associated

with sexual victimisation in Australia, including the cost of correctional treatment, is

estimated to be approximately $775 million (Australian Institute of Criminology,

2014). Some of the many negative emotional impacts of sexual offending on victims

may include fear, self-blame, anxiety, and depression (Letourneau & Borduin, 2008).

Social costs are also experienced by those who sexually harm, many of whom are

removed from their families and face the stigma associated with sexual offending

(Letourneau & Borduin, 2008). Accurate risk assessments and treatments are therefore

necessary to correctly identify and effectively address such behaviours.

Youth Sexual Recidivism Risk Assessment Measures

Until recently, the empirical literature regarding sexual recidivism risk assessment

focused largely on adult populations. Given the primary focus on measures designed

to assess the likelihood of sexual recidivism for adults, sexual recidivism risk assess-

ment measures designed for youth populations are largely lacking (Hempel et al.,

2013). There are limited published studies examining youth sexual recidivism risk

assessment and, as there is a high propensity of youth who also engage in non-sexual

offending prior to and subsequent to sexual offending, it is important to consider

whether these risk assessment measures are accurate for assessing the risk of sexual as

well as non-sexual recidivism for this population (Chu et al., 2012). There are a num-

ber of sexual recidivism risk assessment measures developed for YSH including the

Estimate of Risk of Adolescent Sexual Offense Recidivism (ERASOR; Worling &

Curwen, 2001); Juvenile Sexual Offender Recidivism Risk Assessment Tool-II