Work

Comparing the Different Sets of Item-Level Diagnostic Criteria of the Coma Recovery Scale-Revised (CRS-R): A Measurement-Based Approach Driven by Rasch Analysis

Year: 2024

Type: article

Abstract: Objectives (1) To replicate the assessment of the internal construct validity of the Coma Recovery Scale-Revised (CRS-R) within the Rasch Measurement Theory framework using a larger multicenter sample size and (2) to compare the different sets of item-level diagnostic criteria against the measurement ruler constructed from Rasch analysis to understand how those criteria relate to the overall level of persons' consciousness. Design Multicenter retrospective study. Setting Seven centers. Participants A total of 380 inpatients with a disorder of consciousness with one or more observations, for a total sample of 1460 observations. Interventions Not applicable. Main Outcome Measure CRS-R. Results We created 2 subsamples: a validation subsample of 1 randomized assessment per subject (N=380) and a confirmation subsample using the further available assessments per subject (N=347). The Rasch analyses, conducted on the validation subsample and replicated on the confirmation one, demonstrated adequate satisfaction of all the model's requirements, including monotonicity, unidimensionality, local independence, invariance (χ 2 df =40.224; P =.020), and absence of significant differential item functioning across all person factors explored, including etiology. The reliability (Person Separation Index>0.870) was sufficient for individual person measurement, with the distinction of five Distinct Levels of Performance Ability. The CRS-R rulers based on the Rasch calibration allowed the visual comparison of the various sets of disorder of consciousness diagnostic criteria available, suggesting the possibility of a further refinement of these criteria. Conclusions This study improved the results of a previous Rasch analysis published in 2013. It delivered a new stable Rasch calibration of the CRS-R within the largest multicenter sample size available to date and without any differential item functioning by patient's etiology. The adopted measurement-based approach provided further insights into the diagnostic meaning of several score categories of the CRS-R, confirming previous findings and suggesting that "automatic motor response" (item: motor function) and "object recognition" (item: visual function) are likely to represent behavioral manifestations of MCS+ and eMCS, respectively.

Source: Archives of Physical Medicine and Rehabilitation

DOI: 10.1016/j.apmr.2024.12.009