1. Structuring, Sequencing, Staging, Selecting: the 4S method for the longitudinal analysis of multidimensional measurement scales in chronic diseases
- Author
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Saulnier, Tiphaine, Meissner, Wassilios G., Fabbri, Margherita, Foubert-Samier, Alexandra, and Proust-Lima, Cécile
- Subjects
Statistics - Methodology - Abstract
In clinical studies, measurement scales are often collected to report disease-related manifestations from clinician or patient perspectives. Their analysis can help identify relevant manifestations throughout the disease course, enhancing knowledge of disease progression and guiding clinicians in providing appropriate support. However, the analysis of measurement scales in health studies is not straightforward as made of repeated, ordinal, and potentially multidimensional item data. Their sum-score summaries may considerably reduce information and impend interpretation, their change over time occurs along clinical progression, and as many other longitudinal processes, their observation may be truncated by events. This work establishes a comprehensive strategy in four consecutive steps to leverage repeated data from multidimensional measurement scales. The 4S method successively (1) identifies the scale structure into subdimensions satisfying three calibration assumptions (unidimensionality, conditional independence, increasing monotonicity), (2) describes each subdimension progression using a joint latent process model which includes a continuous-time item response theory model for the longitudinal subpart, (3) aligns each subdimension's progression with disease stages through a projection approach, and (4) identifies the most informative items across disease stages using the Fisher's information. The method is comprehensively illustrated in multiple system atrophy (MSA), an alpha-synucleinopathy, with the analysis of daily activity and motor impairments over disease progression. The 4S method provides an effective and complete analytical strategy for any measurement scale repeatedly collected in health studies.
- Published
- 2024