Limitations in actuarial risk assessment of sexual offenders: a methodological note

Abstract

The assessment of risk of recidivism in sexual offenders is fundamental to clinical practice. It is widely accepted that, compared with actuarial measures of risk, unaided clinical judgment has generally been found to be of low reliability. Consequently, the literature has shown a surge in actuarial measures. However, a major difficulty in assessing risk in sex offenders is the low base rate, leading to an increased likelihood of making a false positive predictive error. To overcome this, risk assessment studies are increasingly using the receiver operating characteristic (ROC), which displays the relationship between level of risk and decision choice. This note summarises the methodological issues in measuring predictive accuracy in assessing risk of re‐offending in sexual offenders, and identifies from the literature both static and dynamic risk factors associated with sexual offence recidivism.