Rates of Sexual Recidivism in High Risk Sex Offenders: A Meta-Analysis of 10,422 Participants

Abstract

Background: Despite the widespread use of structured risk assessment instruments in the prediction of repeat sexual offending, it is not known how stable rates of sexual recidivism are in people classed as high risk. This is important, as high risk classifications are used to justify indeterminate detention decisions in an increasing number of Western countries. We investigated the extent and sources of variation in rates of sexual recidivism in sex offenders found to be high risk by structured risk assessment instruments.

Methods: Studies on eight widely used risk assessment instruments were identified via a systematic search of PsycINFO, EMBASE, MEDLINE, and US National Criminal Justice Reference Service Abstracts (January 1, 1995 to January 1, 2011). Rates of sexual recidivism for offenders classed as high risk were extracted, and binomial logistic regression was used to investigate potential sources of variation, including the population rate of sexual recidivism, sex, age, geographic location, instrument characteristics, and outcome characteristics.

Results: Information on rates of repeat sexual offending was collected on 10,422 unique sex offenders in 29 samples from 21 independent studies. Overall and mean annual rates of sexual recidivism in those classified as high risk varied both within and between instruments. Multivariable binomial logistic regression revealed that odds of sexual recidivism in high risk groups were significantly lower for each year increase in the mean age of the sample, when an actuarial instrument was used, and in studies that relied on conviction as their outcome.

Conclusions: The rate of sexual recidivism in individuals classified as high risk by structured risk assessment instruments varies systematically. Taken alone, a classification of high risk, whether generated by actuarial or structured professional judgment methods, does not imply any particular probability of repeat sexual offending. Recent suggestions that sex offender age is insufficiently weighted by structured instruments warrant clinical attention.

Keywords: Risk Assessment, Sex Offender, Meta-analysis, Forensic, Crime