Going Beyond State of Consciousness: Using Responsiveness Indices to Evaluate Change in Patients with Disorders of Consciousness

Research Objectives: To compare two methods of evaluating change during rehabilitation for people with disorders of consciousness (DoC) after severe traumatic brain injury.

Design: Secondary analysis of data from a randomized controlled trial.

Setting: 11 inpatient rehabilitation facilities.

Participants: 180 participants with DoC who were enrolled in a clinical trial. Participants were between 28-112 days post injury at baseline (mean = 53.6 days, SD = 22.5). At baseline, 119 participants were in the minimally conscious state (MCS) and 61 were categorized to unresponsive wakefulness syndrome (UWS).

Interventions: All participants received standard of care inpatient rehabilitation for four weeks. 92 participants were assigned to the experimental group (i.e., Amantadine HCl) and 88 were assigned to the control group (placebo).

Main Outcome Measures: Coma Recovery Scale – Revised (CRS-R) at baseline and Week 4. We transformed ordinal, raw CRS-R scores into 0-100 equal-interval measures using Rasch analysis. We applied a previously-published minimal detectable change value with a 95% confidence interval (11 units) to determine whether participants improved beyond measurement error. We also used the Aspen consensus criteria to determine whether participants improved state of consciousness.

Results: 64% of participants (115/180) improved beyond measurement error on the CRS-R between baseline and Week 4. 25% of these participants (29/115) remained in the same state of consciousness. 5% of patients (9/180) progressed to a higher state of consciousness based on Aspen criteria but did not improve beyond measurement error. These results suggest that 21% of the sample (38/180) may be misclassified using state change alone. A chi-squared comparing these two methods of evaluating change result in significantly different classifications for participants (χ2=61.9, p<.00001).

Conclusions: The minimal detectable change may capture more individuals making progress than state change. This method may support clinicians in advocating for continued rehabilitation services for individuals in DoC, particularly when they improve within the same state.

Author(s) Disclosures: None.