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Exploratory rasch analysis of a static-99R clinical cohort assessment

Baudin, Christian ; Grimby-Ekman, Anna ; Nilsson, Thomas LU ; Wallinius, Märta LU and Andiné, Peter (2024) In PLoS ONE 19(7 July).
Abstract

Modern test theory supplements the more prevalent classic methods for assessing test properties. However, such an assessment of the commonly used sexual recidivism risk assessment instrument, Static-99R, has yet to be attempted. This study evaluated the psychometric properties of said instrument using Rasch analysis. The clinical cohort assessed consisted of individuals with mental disorders convicted of a sexual offense (N = 146). Results showed that the original ten-item Static-99R did not meet the Rasch model requirements, and revisions of the instrument with seven and nine items each only marginally improved performance. More reliable results could likely have been obtained with a larger, non-clinical sample and a more randomized... (More)

Modern test theory supplements the more prevalent classic methods for assessing test properties. However, such an assessment of the commonly used sexual recidivism risk assessment instrument, Static-99R, has yet to be attempted. This study evaluated the psychometric properties of said instrument using Rasch analysis. The clinical cohort assessed consisted of individuals with mental disorders convicted of a sexual offense (N = 146). Results showed that the original ten-item Static-99R did not meet the Rasch model requirements, and revisions of the instrument with seven and nine items each only marginally improved performance. More reliable results could likely have been obtained with a larger, non-clinical sample and a more randomized distribution of missing data. Despite the consistently poor performance of item 3 (“Index non-sexual violence”) in all three analyses, reliability was slightly improved by dichotomizing the only two polytomous items in the Static-99R; items 1 (“Age at release from index offense”) and 5 (“Prior sexual offenses”). These results may be of interest considering the significant change of splitting the formerly dichotomous item 1 into four different response categories in the revision of Static-99 to Static-99R.

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author
; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
PLoS ONE
volume
19
issue
7 July
article number
e0307216
publisher
Public Library of Science (PLoS)
external identifiers
  • pmid:39024242
  • scopus:85198942552
ISSN
1932-6203
DOI
10.1371/journal.pone.0307216
language
English
LU publication?
yes
id
cd82e0ac-ad59-4519-8e5f-fa2f96feaab9
date added to LUP
2024-09-30 13:50:05
date last changed
2025-07-08 16:16:01
@article{cd82e0ac-ad59-4519-8e5f-fa2f96feaab9,
  abstract     = {{<p>Modern test theory supplements the more prevalent classic methods for assessing test properties. However, such an assessment of the commonly used sexual recidivism risk assessment instrument, Static-99R, has yet to be attempted. This study evaluated the psychometric properties of said instrument using Rasch analysis. The clinical cohort assessed consisted of individuals with mental disorders convicted of a sexual offense (N = 146). Results showed that the original ten-item Static-99R did not meet the Rasch model requirements, and revisions of the instrument with seven and nine items each only marginally improved performance. More reliable results could likely have been obtained with a larger, non-clinical sample and a more randomized distribution of missing data. Despite the consistently poor performance of item 3 (“Index non-sexual violence”) in all three analyses, reliability was slightly improved by dichotomizing the only two polytomous items in the Static-99R; items 1 (“Age at release from index offense”) and 5 (“Prior sexual offenses”). These results may be of interest considering the significant change of splitting the formerly dichotomous item 1 into four different response categories in the revision of Static-99 to Static-99R.</p>}},
  author       = {{Baudin, Christian and Grimby-Ekman, Anna and Nilsson, Thomas and Wallinius, Märta and Andiné, Peter}},
  issn         = {{1932-6203}},
  language     = {{eng}},
  number       = {{7 July}},
  publisher    = {{Public Library of Science (PLoS)}},
  series       = {{PLoS ONE}},
  title        = {{Exploratory rasch analysis of a static-99R clinical cohort assessment}},
  url          = {{http://dx.doi.org/10.1371/journal.pone.0307216}},
  doi          = {{10.1371/journal.pone.0307216}},
  volume       = {{19}},
  year         = {{2024}},
}