The predictive and convergent validity of a psychometric battery used to assess sexual offenders in a treatment programme: an 18-year follow-up

Abstract

This study examined sex offender risk and treatment change based on a battery of psychometric assessment measures administered to 267 treated adult Canadian federal sex offenders followed up an average 18 years post release. Several significant pre–post changes that were frequently moderate in magnitude (d>.50) were observed across these measures. A factor analysis of the psychometric battery generated three broad need domains consistent with the extant literature that were labelled Socioemotional Functioning, Anger/Hostility, and Misogynist Attitudes. The three need domains and a Need Total, created by their summation, converged with the Violence Risk Scale—Sexual Offender version (VRS-SO; Wong, Olver, Nicholaichuk, & Gordon, 2003) in conceptually meaningful ways and predicted sexual and violent recidivism to varying degrees. Raw measurements of change obtained from pre-to posttreatment frequently bore weak and non-significant relationships to outcome. However, after creating standardised residual change scores to control for pre-treatment score, treatment changes in the individual measures, need domains and Need Total improved significantly in their prediction of reductions in general and sexual violence.