title: Rasch analysis of the hospital anxiety and depression scale in patients with chronic fatigue syndrome

authors: Bartholomew, Emerson J.

subjects: Chronic fatigue syndrome

abstract: Background: The Hospital Anxiety and Depression Scale (HADS) is widely utilized for assessing psychological distress in medical populations, yet its clinimetric properties in chronic fatigue conditions remain underexplored. Given the complex symptom presentation in chronic fatigue syndrome (CFS), rigorous clinimetric validation is essential for accurate clinical assessment. 

Objective: This study aimed to evaluate the clinimetric properties of the HADS using Rasch methodology in patients with CFS, with particular emphasis on dimensionality, item functioning, and measurement precision. 

Methods: Rasch analysis was conducted on HADS responses from 286 participants diagnosed with CFS. The Partial Credit Rasch model was applied to assess overall model fit, item performance, unidimensionality and differential item functioning. 

Results: Initial analysis revealed suboptimal model fit, necessitating subtest modifications to address local response dependence. The subtest solution demonstrated acceptable fit to the Rasch model with evidence of strict unidimensionality, high reliability (PSI = 0.87), and no differential item functioning by demographic variables. Rasch-converted interval scores showed improved measurement precision compared to ordinal scoring. Interval scoring yielding a significantly higher mean (M = 22.55, SD = 3.78) compared to unconverted scoring (M = 20.30, SD = 6.87), t(275) = −19.54, p < .001, indicating that ordinal scoring systematically underestimates the latent trait level. Interval scores showed a 45 % reduction in measurement error demonstrated by the substantial reduction in standard error. 

Conclusions: The HADS demonstrated acceptable measurement properties in patients with CFS. The development of ordinal-to-interval conversion tables enhances the scale's precision, supporting its continued use in clinical and research contexts.

text: Rasch analysis of the hospital anxiety and depression scale in patients with chronic fatigue syndrome Background: The Hospital Anxiety and Depression Scale (HADS) is widely utilized for assessing psychological distress in medical populations, yet its clinimetric properties in chronic fatigue conditions remain underexplored. Given the complex symptom presentation in chronic fatigue syndrome (CFS), rigorous clinimetric validation is essential for accurate clinical assessment. 

Objective: This study aimed to evaluate the clinimetric properties of the HADS using Rasch methodology in patients with CFS, with particular emphasis on dimensionality, item functioning, and measurement precision. 

Methods: Rasch analysis was conducted on HADS responses from 286 participants diagnosed with CFS. The Partial Credit Rasch model was applied to assess overall model fit, item performance, unidimensionality and differential item functioning. 

Results: Initial analysis revealed suboptimal model fit, necessitating subtest modifications to address local response dependence. The subtest solution demonstrated acceptable fit to the Rasch model with evidence of strict unidimensionality, high reliability (PSI = 0.87), and no differential item functioning by demographic variables. Rasch-converted interval scores showed improved measurement precision compared to ordinal scoring. Interval scoring yielding a significantly higher mean (M = 22.55, SD = 3.78) compared to unconverted scoring (M = 20.30, SD = 6.87), t(275) = −19.54, p < .001, indicating that ordinal scoring systematically underestimates the latent trait level. Interval scores showed a 45 % reduction in measurement error demonstrated by the substantial reduction in standard error. 

Conclusions: The HADS demonstrated acceptable measurement properties in patients with CFS. The development of ordinal-to-interval conversion tables enhances the scale's precision, supporting its continued use in clinical and research contexts.

year: 2025

title: Superantigen architecture: Functional decoration on a conserved scaffold

authors: Arcus, Vickery L.

subjects: biology

abstract: A defining and consistent feature of the bacterial superantigens from Staphylococcus aureus and Streptococcus pyogenes is their strongly conserved three-dimensional structure. Structural studies to date show that the array of more than 280 amino acid sequences known for superantigens (SAgs) and staphylococcal superantigen-like (SSL) proteins all have the same fold-a structure in which the same three-dimensional arrangement of α-helices and β-sheets is traced by each amino acid sequence, with the same topology (for recent reviews, see references 29 and 43). A typical SAg structure comprises two domains-an N-terminal β -barrel domain called an OB-fold (4, 25) and a C-terminal β-grasp domain in which a long α-helix packs on to a mixed parallel and antiparallel β-sheet. These two domains are traversed by an α-helix that lies at the N terminus of the protein and packs against the β-grasp domain, thus linking the N- and C-terminal domains.

text: Superantigen architecture: Functional decoration on a conserved scaffold A defining and consistent feature of the bacterial superantigens from Staphylococcus aureus and Streptococcus pyogenes is their strongly conserved three-dimensional structure. Structural studies to date show that the array of more than 280 amino acid sequences known for superantigens (SAgs) and staphylococcal superantigen-like (SSL) proteins all have the same fold-a structure in which the same three-dimensional arrangement of α-helices and β-sheets is traced by each amino acid sequence, with the same topology (for recent reviews, see references 29 and 43). A typical SAg structure comprises two domains-an N-terminal β -barrel domain called an OB-fold (4, 25) and a C-terminal β-grasp domain in which a long α-helix packs on to a mixed parallel and antiparallel β-sheet. These two domains are traversed by an α-helix that lies at the N terminus of the protein and packs against the β-grasp domain, thus linking the N- and C-terminal domains.

year: 2007

title: He reo amiorangi

authors: Roa, Tom

subjects: Māori language

abstract: This paper discusses a project involving the translation of a learning management system (LMS), Modular Object-Oriented Dynamic Learning Environment (Moodle), into te reo Māori so that users of this LMS, learners, teachers and administrators who have a high level of competence in the language, can work within a fully Māori environment. Aspects of the project referred to here include adaptation of the style guide created by Te Taura Whiri for the Microsoft project, use of the Microsoft translation guidelines, the philosophy guiding the translation and the translation process itself (with examples). The process by which the project was evaluated is also discussed.

text: He reo amiorangi This paper discusses a project involving the translation of a learning management system (LMS), Modular Object-Oriented Dynamic Learning Environment (Moodle), into te reo Māori so that users of this LMS, learners, teachers and administrators who have a high level of competence in the language, can work within a fully Māori environment. Aspects of the project referred to here include adaptation of the style guide created by Te Taura Whiri for the Microsoft project, use of the Microsoft translation guidelines, the philosophy guiding the translation and the translation process itself (with examples). The process by which the project was evaluated is also discussed.

year: 2006