Revalidation of the Custody Rating Scale for Indigenous
Men Offenders
What we did
The predictive validity of the CRS for Indigenous men offenders was assessed using a dataset of admissions to federal custody between 2013/2014 and 2018/2019. The dataset included Indigenous men offenders admitted to federal custody on a Warrant of Committal (WOC, i.e., a new sentence; N = 5,967) or following a revocation of conditional release
(N = 2,023).
What we found
A higher CRS designation was associated with a greater likelihood of involvement in a negative institutional event (see Table 1). The association was stronger for new admissions relative to revocation admissions. A similar pattern was evident in the case of OSL. Area Under the Curve (AUC) values reached the threshold of ‘good’ predictive accuracy for the CRS in relation to involvement in an institutional incident, and ‘acceptable’ predictive accuracy in the case of an institutional charge. Predictive accuracy was similar for OSL relative to CRS. However, predictive accuracy was lower for the revocation group in the case of both the CRS and OSL (see Table 2).
What it means
The results of the present study reaffirm the predictive validity of the CRS for Indigenous men offenders at intake, as well as the efficacy of professional judgement, as evidenced by the similar predictive ability of the CRS and OSL. However, predictive accuracy was found to be weaker in the case of revocation admissions.
Table 1. Institutional Outcomes by CRS Designation for Indigenous Men Offenders Admitted on a WOC or Revocation, 2013/2014 to 2018/2019.
CRS Level |
|||||||
| Outcome | Warrant of Committal (WOC) |
Revocation |
|||||
Min. |
Med. |
Max. |
Min. |
Med. |
Max. |
||
Incident a |
39% |
68% |
93% |
29% |
43% |
61% |
|
Charge b |
35% |
66% |
87% |
24% |
39% |
49% |
|
Table 2. Predictive Ability of CRS and WOC for Indigenous Men Offenders Admitted on a WOC or Revocation, 2013/2014 to 2018/2019.
Receiver Operating Characteristic (ROC) Analyses |
||||
Outcome |
WOC |
Revocations |
||
AUC * |
CI |
AUC * |
CI |
|
Custody Rating Scale (CRS) |
||||
Incident a |
.700 |
.688-.712 |
.583 |
.563-.602 |
Charge b |
.683 |
.671-.695 |
.558 |
.537-.578 |
Offender Security Level (OSL) |
||||
Incidenta |
.682 |
.670-.693 |
.585 |
.567-.603 |
Chargeb |
.661 |
.650-.673 |
.547 |
.529-.566 |
a Refers to involvement in at least one security or behavioural incident during the sentence for which the CRS was applied and following CRS administration.
b Refers to an offender’s receipt of any serious or minor disciplinary charge during the sentence for which the CRS was applied and following CRS administration. Only charges resulting in an outcome of ‘guilty’ were included.
* The Area Under the Curve (AUC) is used to examine the predictive accuracy of a measure in ROC analyses; a value of 0.5 represents chance prediction, while a value of 1.0 represents perfect prediction.
Note. CI = Confidence Interval
References:
Gobeil, R. (2011). The Custody Rating Scale as applied to male offenders (Research Report R-256). Ottawa, ON: Correctional Service of Canada.
For more information
To obtain a PDF version of the full report, or for other inquiries, please e-mail the Research Branch.
You can also visit the Research Publications section for a full list of reports and one-page summaries.
Prepared by: The Special Projects and Data Management (SPDM) team.