Predictive Validity and Sensitivity to Change of the Neurological Outcome Scale for Traumatic Brain Injury (S49.002)

Abstract

Objective: The Neurological Outcome Scale for Traumatic Brain Injury (NOS-TBI) is a measure designed to assess neurological functioning in traumatic brain injury (TBI) across the spectrum of recovery. We hypothesized the NOS-TBI would demonstrate predictive validity and be more sensitive to change than other well-established measures. Background Clinical trials in TBI frequently rely on a single global outcome measure. Available tools do not provide an assessment of neurological functioning, per se. We recently developed a measure of neurological functioning in TBI, the NOS-TBI. While the NOS-TBI has been validated in patients with TBI undergoing rehabilitation up to 18 months post-injury, its performance in TBI-related clinical trials and its sensitivity to change over time are unknown. Design/Methods: We analyzed data from the National Acute Brain Injury Study: Hypothermia-II (NABIS:H-II) clinical trial. Patients were 16-45 years with severe TBI, assessed at 3, 6, and 12 months post-injury. A subset was assessed at 1 month. For analysis of criterion-related validity, Spearman correlations were performed comparing the NOS-TBI to Glasgow Outcome Scale (GOS), GOS-Extended (GOS-E), Disability Rating Scale (DRS), and Marshall CT classification. Sensitivity to change was analyzed using the Wilcoxon signed-rank sum test. Results: Significant correlation was observed between the NOS-TBI and the GOS, GOS-E, DRS, and NRS-R total scores, demonstrating the concurrent validity of these tools. The GCS, Marshall CT classification, and lesion volume demonstrated overall limited ability to predict outcome at 3, 6, and 12 months post-injury. In contrast, the NOS-TBI total score at both 1 and 3-months post-injury demonstrated a significant ability to predict outcome at 3, 6, and 12 months post-injury. Trial subjects whose recovery appeared to have stabilized based on GOS and GOS-E scores, demonstrated significant changes in their level of neurologic recovery using the NOS-TBI. Conclusions: The NOS-TBI demonstrated significantly better outcome prediction and sensitivity to change compared with well-established outcome measures. Supported by: In part by grant NS 43353 from the NIH/NINDS, Guy L. Clifton, Principal Investigator. Disclosure: Dr. Moretti has nothing to disclose. Dr. McCauley has nothing to disclose. Dr. Wilde has nothing to disclose. Dr. Levin has nothing to disclose. Dr. Clifton has nothing to disclose.