e-space
Manchester Metropolitan University's Research Repository

Unidimensionality of the Strengths and Vulnerabilities Scales in the Short-Term Assessment of Risk and Treatability (START)

Whittington, Richard and Pollak, Charlotte and Keski-Valkama, Alice and Brown, Andrew and Haines-Delmont, Alina and Bak, Jesper and Hvidhjelm, Jacob and Almvik, Roger and Palmstierna, Tom (2021) Unidimensionality of the Strengths and Vulnerabilities Scales in the Short-Term Assessment of Risk and Treatability (START). International Journal of Forensic Mental Health. pp. 1-10. ISSN 1499-9013

[img]
Preview

Available under License Creative Commons Attribution Non-commercial No Derivatives.

Download (1MB) | Preview

Abstract

The Short-Term Assessment of Risk and Treatability (START) is a 20-item structured professional judgment instrument for assessing dynamic risk in mental health services. Much of the START research literature examines the relationship between Strengths and Vulnerabilities sub-scale total scores and various adverse outcomes including violence. This assumes that the two sub-scales have the psychometric property of unidimensionality i.e. all the items cluster together as a measure of a single construct. Such assumed unidimensionality is a necessary condition for any analyses based on scale “total score” and the widespread use of scores summated in this way in research studies may obscure more specific clusters of items within each sub-scale. This multinational study examined START assessments (n = 685) conducted in four forensic services in Scandinavia and the UK using principal component analysis. It was found that all but three Strengths items (Substance Use, Social Support and Material Resources) and all but four Vulnerabilities items (Substance Use, Social Support, Material Resources and Self care) loaded >0.5 on the expected component. This indicates a unidimensional structure underlying the START and provides empirical support from a large multinational sample for the widespread use of summated Strengths and Vulnerabilities scores in forensic psychiatric risk research.

Impact and Reach

Statistics

Downloads
Activity Overview
5Downloads
20Hits

Additional statistics for this dataset are available via IRStats2.

Altmetric

Actions (login required)

View Item View Item