Psychometric properties of MG-ADL items and MG-ADL score: An assessment of distributional characteristics, validity and factor structure in two large datasets
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引用次数: 0
Abstract
Background
The Myasthenia Gravis–Activities of Daily Living scale (MG-ADL) is an 8-item outcome measure to assess symptoms and functional limitations in myasthenia gravis (MG) patients. The MG-ADL score is an equally weighted level sum score that is used as primary outcome measures in clinical trials, in clinical practice, and as an end-point in health economic evaluation. This data analysis aims to obtain detailed knowledge of measurement properties of MG-ADL items and the MG-ADL score.
Methods
Cross-sectional data from a real-world prospective study (MRW) were combined with longitudinal data from the ADAPT trial. Outcome measures included were MG-ADL, Quantitative Myasthenia Gravis score (QMG), MG 15-item Quality of Life (MG-QOL15r) and EQ-5D-5L. Patients were categorized by their Myasthenia Gravis Foundation of America (MGFA) clinical classification. The following measurement properties were assessed: distributional characteristics, inter-item correlation, convergent, known groups and construct validity and internal factor structure.
Results
Correlations of items within MG-ADL dimensions were moderate, while MG-ADL correlations between comparable MG-QOL15r and QMG items were mixed. Known groups validity for the MG-ADL score was demonstrated for MGFA class. Mean MG-ADL item level scores by MGFA class demonstrated construct validity. PCA, including all four outcome measures, resulted in a nine factor solution.
Discussion
Psychometric properties of individual MG-ADL items were moderate to good. This study showed that the MG-ADL adequately captures the multidimensional heterogeneous nature of MG. This is, however, accompanied by mixed psychometric performance of the MG-ADL score, which may complicate health economic modelling.
Registration: MyRealWorld-MG was registered on November 25, 2019, with registration numberNCT04176211. The ADAPT randomized clinical trial is registered atClinicalTrials.gov(NCT03669588).
期刊介绍:
The Journal of the Neurological Sciences provides a medium for the prompt publication of original articles in neurology and neuroscience from around the world. JNS places special emphasis on articles that: 1) provide guidance to clinicians around the world (Best Practices, Global Neurology); 2) report cutting-edge science related to neurology (Basic and Translational Sciences); 3) educate readers about relevant and practical clinical outcomes in neurology (Outcomes Research); and 4) summarize or editorialize the current state of the literature (Reviews, Commentaries, and Editorials).
JNS accepts most types of manuscripts for consideration including original research papers, short communications, reviews, book reviews, letters to the Editor, opinions and editorials. Topics considered will be from neurology-related fields that are of interest to practicing physicians around the world. Examples include neuromuscular diseases, demyelination, atrophies, dementia, neoplasms, infections, epilepsies, disturbances of consciousness, stroke and cerebral circulation, growth and development, plasticity and intermediary metabolism.