Sensitivity and Specificity of the Coma Recovery Scale–Revised Total Score in Detection of Conscious Awareness

Abstract

Objective The aim of this report is to describe the sensitivity and specificity of Coma Recovery Scale-Revised (CRS-R) total scores in detecting conscious awareness. Design Data were retrospectively extracted from the medical records of patients enrolled in a specialized Disorders of Consciousness (DoC) program. Sensitivity and specificity analyses were completed using CRS-R-derived diagnoses of Minimally Conscious State (MCS) or Emerged from Minimal Conscious State (EMCS) as the reference standard for conscious awareness and the total CRS-R score as the “test criterion”. A receiver operating curve (ROC) was constructed to demonstrate the optimal CRS-R total cut-off score for maximizing sensitivity and specificity. Setting Specialized DoC program Participants 252 patients enrolled in the DoC program (157 male; mean age = 49 years; mean time from injury =48 days; traumatic etiology=127, non-traumatic etiology=125; diagnosis of coma or VS=72, diagnosis of MCS or EMCS=182) Interventions Not applicable. Main Outcome Measure(s) Sensitivity and specificity of CRS-R total scores in detecting conscious awareness Results A CRS-R total score of 10 or higher yielded a sensitivity of 0.78 for correct identification of patients in MCS or EMCS, and specificity of 1.00 for correct identification of patients who did not meet criteria for either of these diagnoses (i.e., were diagnosed with VS or coma). The area under the curve (AUC) in the ROC analysis is 0.98. Conclusion(s) A total CRS-R score of 10 or higher provides strong evidence of conscious awareness but resulted in a false negative diagnostic error in 22% of patients who demonstrated conscious awareness based on CRS-R diagnostic criteria . A cut-off score of 8 provides the best balance between sensitivity and specificity, accurately classifying 93% of cases. The “optimal” total score cut-off will vary depending on the user's objective.

Outcome prediction in disorders of consciousness: the role of coma recovery scale revised

“…The main limitation of this study is that the outcomes at 2 months cannot be considered as definitive. Although the detected predictors are similar to those reported in long-term longitudinal studies [9][10][11][12][13][14][15][16][17][18][19][20][21], we are aware that this study needs further evaluation before translating to clinical practice. Again, the lack of a deeper evaluation of medical complications might have influenced our data.…”

The repetition of behavioral assessments in diagnosis of disorders of consciousness

“…The clinical diagnosis is thus based on the presence or absence of operationally defined behavioral responses to specific sensory stimuli (eg, if a response to command like “move your feet” is observed at least three times out of four trials, the patient is considered to be in MCS + ). We here did not use the total score made up from the addition of the different subscales, because even though a recent study proposed a cut‐off score of 8 to distinguish between patients in UWS/VS and MCS, it still misclassified 7% of patients . A modified score was then proposed, permitting to distinguish UWS/VS and MCS patients, based on the presence of signs of consciousness during the assessment .…”

Detection and Interpretation of Impossible and Improbable Coma Recovery Scale-Revised Scores

“…All assessment procedures and scoring criteria are operationally-defined and the diagnostic criteria for coma, VS, MCS and EMCS are embedded within the scale. The total score can be used to gauge the general trajectory of recovery over time as higher scores reflect progressively increasing levels of neurobehavioral function [8]. …”