Evaluating the Hierarchy of Rating Scale Categories for the Coma Recovery Scale-Revised in Non-Traumatic Brain Injury: A Rasch Analysis.

This article evaluates the psychometric properties and diagnostic validity of the Coma Recovery Scale-Revised (CRS-R) rating scale categories (RSCs) in individuals with disorders of consciousness (DoC) due to non-traumatic brain injury (nTBI). Using Rasch analysis on 4,562 CRS-R assessments from 410 patients, the study found strong reproducibility, structural validity, and measurement accuracy of the CRS-R in this population, though some disordered thresholds were identified in the Motor and Visual items. The findings suggest that certain RSCs currently aligned with unresponsive wakefulness syndrome (UWS) may overlap with minimally conscious state (MCS) indicators, and that consistent command following (Auditory RSC 4) and sustained attention (Arousal RSC 3) may better indicate emergence from MCS (eMCS). The study highlights the need for refinement of CRS-R diagnostic criteria and rating scales to improve sensitivity and interpretability specifically for nTBI patients, emphasizing differences from traumatic brain injury populations, particularly regarding visual function.