Inventory of Offender Risk, Needs, and Strengths（IORNS）日本語版の作成および併存的妥当性の検討

抄録

In Japan, the development of simple tools for assessing the risk of recidivism is an urgent and critical issue to enhance recidivism prevention. To address this concern, we developed the Japanese version of the Inventory of Offender Risk, Needs, and Strengths (IORNS), a self-administered, questionnaire-based tool designed to assess recidivism risk. The IORNS consists of three components—static risk, dynamic needs, and protective strengths —and has been standardized for male and female offenders in the United States. This study examined the reliability and concurrent validity of the Japanese IORNS using a sample of 146 male and female offenders recruited from offender rehabilitation facilities, specialized medical institutions for addiction, and addiction rehabilitation centers in Japan. The results indicated that, consistent with the original instrument, the Japanese IORNS demonstrated high internal consistency across all factors. In addition, the overall risk index and dynamic needs component showed significant positive associations with pathological personality traits, drug dependence, aggression, and psychopathy. Furthermore, the protective strengths component exhibited significant positive associations with self-control and social support. These findings indicate that the Japanese IORNS has a high level of validity within a Japanese offender population. Further research is required to collect normative data for standardizing the tool among male and female offenders in Japan.