Validity of the Telephone-Administered Coma Recovery Scale-Revised and Confusion Assessment Protocol for Standardized Remote Assessment of Persons with Disorders of Consciousness

Research Objectives To develop and evaluate the validity of two telephone-based caregiver interviews (i.e., Telephone-Administered Coma Recovery Scale-Revised [CRS-R] and Confusion Assessment Protocol [CAP]), to enable remote assessment of level of consciousness and basic cognition in persons with disorders of consciousness. Design Caregivers completed the telephone-administered versions of the CRS-R and CAP followed by in-person assessment of patients using the standard CRS-R and CAP. Examiners who administered the in-person CRS-R and CAP were blind to the results of the caregiver interview and vice-versa. Setting Five inpatient rehabilitation hospitals. Participants A convenience sample of persons with disorders of consciousness (DoC) (n=48, mean [SD] age=32 [15]; 31% female) and their caregivers (n=48, mean [SD] age=53 [12]; 75% female). Interventions N/A. Main Outcome Measures We calculated the accuracy and corresponding 95% confidence intervals (CIs) for each of the 9 telephone CRS-R and 8 CAP caregiver interview questions. We defined accuracy as the frequency with which the caregiver and study staff examiner assigned the same rating for each behavior assessed. We calculated the average score of the 17 telephone questions and assessed the agreement between caregiver and staff ratings using Lin's concordance correlation coefficient (CCC) with 95% CIs. We used the in-person examination as the reference standard for all analyses and set the cut-point for acceptable agreement at 0.70. Results The average accuracy of the 9 CRS-R and 8 CAP telephone-based questions was 0.73 and 0.64, respectively. Accuracy values met or exceeded the 0.70 cut-off on 8 of the 9 CRS-R questions and 4 of the 9 CAP questions. Lin's CCC for agreement between caregiver and staff ratings was 0.9 (CI: 0.83, 0.96) across the CRS-R and 0.32 (CI: -.14, 0.76) across the CAP questions. Conclusions The telephone-administered CRS-R appears to be a valid (i.e., accurate) method of assessing and monitoring longitudinal changes in level of consciousness in persons with DoC. Validity indices were insufficient to support use of the telephone-administered CAP. Additional investigation with larger samples should be conducted to further assess the diagnostic utility of both measures. Author(s) Disclosures None.