Is more better? Combining actuarial risk scales to predict recidivism among adult sex offenders

Psychol Assess. 2005 Jun;17(2):156-67. doi: 10.1037/1040-3590.17.2.156.


The present study was conducted to determine whether combining the results of multiple actuarial risk scales increases accuracy in predicting sex offender recidivism. Multiple methods of combining 4 validated actuarial risk scales--the Violence Risk Appraisal Guide, the Sex Offender Risk Appraisal Guide, the Rapid Risk Assessment for Sexual Offense Recidivism, and the Static-99--were evaluated in a sample of 215 adult male sex offenders. These included the intuitively appealing believe-the-negative and believe-the-positive rules, adapted from medical decision making; the combination of absolute decision thresholds across a range of cutoff scores; and the statistical optimization methods of logistic regression and principal components analyses. No combination method provided a statistically significant or consistent advantage over the predictive accuracy of the single best actuarial scale.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Decision Making
  • Humans
  • Logistic Models
  • Male
  • Models, Psychological*
  • ROC Curve
  • Recurrence
  • Risk Factors
  • Sex Offenses / statistics & numerical data*
  • Surveys and Questionnaires
  • Time Factors