10779/rcsi.10772303.v1
Frank Doyle
Frank
Doyle
Roger Watson
Roger
Watson
Karen Morgan
Karen
Morgan
Orla McBride
Orla
McBride
A hierarchy of distress and invariant item ordering in the General Health Questionnaire-12
Royal College of Surgeons in Ireland
2019
Non-parametric Item Response Theory
General Health Questionnaire
Psychological Distress
Psychology and Cognitive Sciences not elsewhere classified
2019-11-22 15:36:40
Journal contribution
https://repository.rcsi.com/articles/journal_contribution/A_hierarchy_of_distress_and_invariant_item_ordering_in_the_General_Health_Questionnaire-12/10772303
<p>Background: Invariant item ordering (IIO) is defined as the extent to which items have thesame ordering (in terms of item difficulty/severity – i.e. demonstrating whether</p>
<p>items are difficult [rare] or less difficult [common]) for each respondent who completes a scale. IIO is therefore crucial for establishing a scale hierarchy that is replicable across samples, but no research has demonstrated IIO in scales of psychological distress. We aimed to determine if a hierarchy of distress with IIO exists in a large general population sample who completed ascale measuring distress.</p>
<p>Methods: Data from 4107 participants who completed the 12-item General Health Questionnaire (GHQ-12) from the Northern Ireland Health and Social Wellbeing Survey 2005-6 were analysed. Mokken scaling was used to determine the dimensionality and hierarchy of the GHQ-12, and items were investigated for IIO.</p>
<p>symptoms reflected the following hierarchy: anhedonia, concentration, participation, coping, decision-making and worthlessness.</p>
<p>Results: All items of the GHQ-12 formed a single, strong unidimensional scale (H=0.58). IIO was found for six of the 12 items (H-trans=0.55), and these</p>
<p>Limitations: The cross-sectional analysis needs replication.</p>
<p>Conclusions: The GHQ-12 showed a hierarchy of distress, but IIO is only demonstrated for six of the items, and the scale could therefore be shortened. Adopting brief, hierarchical scales with IIO may be beneficial in both a clinical and research context.</p>