Assessing the risk of re-offending in adults: GRAM 2

E.Stavrou1*, J.Trevena1, S.Poynton1

1- NSW Bureau of Crime Statistics and Research

*corresponding author:


In order to allocate scarce resources more efficiently, risk assessment tools are viewed as a cost-effective method for identifying individuals at-risk of reoffending and are therefore becoming increasingly favoured by criminal justice agencies due to their relative efficiency and ease of use.


To re-examine the Group Risk Assessment Model (GRAM) for determining factors which predict re-offending in adults given non-custodial sentences and to assess the accuracy and usefulness of the model.


Adult offenders given non-custodial sentences in 2011 were our cohort of interest. Our outcome was reoffending within 24 months of the index appearance which was obtained using court data. Models predicting reoffending using personal, index offence and criminal history characteristics were undertaken using multivariate logistic regression and model fits were assessed. Model validity and reliability was also measured by applying the model estimates to sub-group data and to separate smaller cohorts.


Of the 81,199 adult offenders, 26% reoffended within two years of the index appearance. The best model fit for GRAM 2 was age, gender, Indigenous status, number of concurrent offences, prior custodial sentence, prior proven offences and the index offence type. The internal and external validity of the model was strong, however application of the model to offenders from smaller geographical areas, Indigenous offenders or to those with specific criminal history should be undertaken with care. Application of the model for screening purposes should also be carefully considered.


The GRAM 2 has been shown to be a robust tool for predicting reoffending and although reliable, the model and its applicability should be re-examined periodically.


Efty’s experience has been grounded in conducting population investigations in the allied health, public health and epidemiological fields. She has extensively analysed large administrative datasets both singularly and in longitudinal data linkage . She is experienced in evaluating interventions including developing program logics and assessing evaluation questions, and to evaluate the impact of interventions in pilot sites and on the system. Efty is currently a Senior Research Office with the NSW Bureau of Crime Statistics and Research.

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