Developing Nonarbitrary Metrics for Risk Communication

2016 ◽  
Vol 43 (12) ◽  
pp. 1661-1687 ◽  
Author(s):  
Robert J. B. Lehmann ◽  
David Thornton ◽  
L. Maaike Helmus ◽  
R. Karl Hanson
Keyword(s):  
Risk Communication ◽  
Sexual Offenders ◽  
Evidence Based ◽  
Risk Matrix ◽  
Recidivism Rates ◽  
Violent Recidivism ◽  
Actuarial Risk Assessment ◽  
Actuarial Risk ◽  
Risk Ratios ◽  
Risk Categories

Nominal risk categories for actuarial risk assessment information should be grounded in nonarbitrary, evidence-based criteria. The current study presents numeric indicators for interpreting one such tool, the Risk Matrix 2000, which is widely used to assess the recidivism risk of sexual offenders. Percentiles, risk ratios, and 5-year recidivism rates are presented based on an aggregated sample ( N = 3,144) from four settings: England and Wales, Scotland, Germany, and Canada. The Risk Matrix 2000 Sex, Violence, and Combined scales showed moderate accuracy in assessing the risk of sexual, non-sexual violent, and violent recidivism, respectively. Although there were some differences across samples in the distributions of risk categories, relative increases in recidivism for ascending risk categories were remarkably consistent. Options for presenting percentiles, risk ratios, and absolute recidivism estimates in applied evaluations are offered, with discussion of the advantages, disadvantages, and limitations of these risk communication metrics.

Assessing the Calibration of Actuarial Risk Scales

2016 ◽  
Vol 44 (1) ◽  
pp. 26-39 ◽  
Author(s):  
R. Karl Hanson
Keyword(s):  
Survival Data ◽  
Predictive Accuracy ◽  
Assessment Tools ◽  
Expected Number ◽  
Recidivism Rates ◽  
Risk Assessment Tools ◽  
Actuarial Risk Assessment ◽  
Alternative Approaches ◽  
Actuarial Risk

Assessing the predictive accuracy of actuarial risk assessment tools requires consideration of discrimination (the differences between recidivists and nonrecidivists) and calibration (the credibility of the recidivism rates associated with test scores or categories). Currently, there are no conventions for reporting calibration effect sizes for offender risk tools. This article explains one promising calibration effect size statistic (the Expected/Observed [E/O] index) and provides an illustrative example of how it can be calculated and interpreted. Briefly, the E/O index is the ratio of the expected number of recidivists to the observed number of recidivists. Guidance is provided for calculating the E/O index with fixed follow-up data as well as from survival data. This article also discusses alternative approaches to examining calibration and provides references to other studies using the E/O index to assess the calibration of offender risk scales.

Improving Risk Communication: Developing Risk Ratios for the VRAG-R

2020 ◽  
pp. 088626052091455
Author(s):  
Simon T. Davies ◽  
L. Maaike Helmus ◽  
Vernon L. Quinsey
Keyword(s):  
Logistic Regression ◽  
Risk Communication ◽  
Cox Regression ◽  
Accurate Estimate ◽  
Data Set ◽  
Violent Recidivism ◽  
Risk Framework ◽  
Rate Ratios ◽  
Risk Ratios

We developed a set of risk ratios for the Violence Risk Appraisal Guide—Revised (VRAG-R) to broaden the range of risk communication options available when using this tool and to provide information needed for future efforts to apply The Council of State Governments Justice Center’s standardized five-level risk framework to the scale. A slightly reduced version of the VRAG-R normative data set was used for the analyses ( N = 1,238). Contrary to previous research developing risk ratios, logistic regression provided a more accurate estimate of observed violent recidivism rates than Cox regression for both total VRAG-R scores and VRAG-R decile bins. Further analyses indicated the relationship between the VRAG-R and violent recidivism was consistent over a 15-year follow-up period. Due to the difficulties with interpreting odds ratios, the final risk ratios were computed using rate ratios derived from a logistic regression model using a 5-year fixed follow-up period. These risk ratios, and templates for how the ratios might be used in an assessment report, are presented in the appendices.

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

2004 ◽  
Vol 6 (1) ◽  
pp. 16-32 ◽  
Author(s):  
Leam Craig ◽  
Kevin Browne ◽  
Ian Stringer ◽  
Anthony Beech
Keyword(s):  
Risk Assessment ◽  
Sexual Offenders ◽  
Actuarial Risk Assessment ◽  
Actuarial Risk

scholarly journals Using Graphs to Improve Violence Risk Communication

2016 ◽  
Vol 44 (5) ◽  
pp. 678-694 ◽  
Author(s):  
N. Zoe Hilton ◽  
Elke Ham ◽  
Kevin L. Nunes ◽  
Nicole C. Rodrigues ◽  
Cairina Frank ◽  
...  
Keyword(s):  
Risk Communication ◽  
Undergraduate Students ◽  
Lower Risk ◽  
Violence Risk ◽  
Violent Recidivism ◽  
Effective Decision ◽  
Actuarial Risk ◽  
Effective Decision Making ◽  
Statistical Risk ◽  
Forensic Risk

We examined the use of graphs as an aid to communicating statistical risk among forensic clinicians. We first tested four graphs previously used or recommended for forensic risk assessment among 442 undergraduate students who made security recommendations about two offenders whose risk differed by one actuarial category of risk for violent recidivism (Study 1). Effective decision making was defined as actuarially higher risk offenders being assigned to greater security than lower risk offenders. The graph resulting in the largest distinction among less numerate students was a probability bar graph. We then tested this graph among 54 forensic clinicians (Study 2). The graph had no overall effect. Among more experienced staff, however, decisions were insensitive to actuarial risk in the absence of the graph and in the desirable direction with the addition of the graph. Further research into the benefit of graphs in violence risk communication appears viable.

Sign in / Sign up

Export Citation Format

Share Document