The Predictive Properties of Dynamic Sex Offender Risk Assessment Instruments: A Meta-Analysis
This meta-analysis is the first to our knowledge to evaluate the predictive properties of dynamic sex offender risk assessment instruments, which are designed to assess factors associated with recidivism that are amenable to change. Based on 52 studies (N = 13,446), we found that dynamic risk assessment instruments have small-to-moderate predictive properties, with Cohen’s d ranging between 0.71 for sexual recidivism (41 studies, 22 unique samples, N = 5,699) and 0.43 for violent (including sexual) recidivism (27 studies, 14 unique samples, N = 10,368). Incremental predictive validity of dynamic over static risk assessment instruments was significant but modest; Cox hazard ratios varied between 1.08 for sexual recidivism (19 studies, 13 unique samples, N = 3,747) and 1.05 for any recidivism (11 studies, 8 unique samples, N = 2,511). Cox hazard ratios for the predictive validity of change scores on dynamic risk assessment instruments, controlling for static and initial dynamic scores, varied between 0.91 for sexual recidivism (6 studies, 6 unique samples, n = 1,980) and 0.95 for any recidivism (3 studies, 3 unique samples, n = 1,172). These findings indicate that dynamic risk assessment instruments can, in terms of Andrews and Bonta’s (2010) risk and need principles, be a useful tool for improving sex offender treatment. They have the potential to contribute to the selection of appropriate, more individually tailored treatment approaches (focusing on individually relevant criminogenic need factors) and can assist in the evaluation of treatment effects. Considering this, further development of dynamic risk assessment instruments is warranted.