Neurological outcome scale for traumatic brain injury: III. Criterion-related validity and sensitivity to change in the NABIS hypothermia-II clinical trial.

The neurological outcome scale for traumatic brain injury (NOS-TBI) is a measure assessing neurological functioning in patients with TBI. We hypothesized that the NOS-TBI would exhibit adequate concurrent and predictive validity and demonstrate more sensitivity to change, compared with other well-established outcome measures. We analyzed data from the National Acute Brain Injury Study: Hypothermia-II clinical trial. Participants were 16-45 years of age with severe TBI assessed at 1, 3, 6, and 12 months postinjury. For analysis of criterion-related validity (concurrent and predictive), Spearman's rank-order correlations were calculated between the NOS-TBI and the glasgow outcome scale (GOS), GOS-extended (GOS-E), disability rating scale (DRS), and neurobehavioral rating scale-revised (NRS-R). Concurrent validity was demonstrated through significant correlations between the NOS-TBI and GOS, GOS-E, DRS, and NRS-R measured contemporaneously at 3, 6, and 12 months postinjury (all p<0.0013). For prediction analyses, the multiplicity-adjusted p value using the false discovery rate was <0.015. The 1-month NOS-TBI score was a significant predictor of outcome in the GOS, GOS-E, and DRS at 3 and 6 months postinjury (all p<0.015). The 3-month NOS-TBI significantly predicted GOS, GOS-E, DRS, and NRS-R outcomes at 6 and 12 months postinjury (all p<0.0015). Sensitivity to change was analyzed using Wilcoxon's signed rank-sum test of subsamples demonstrating no change in the GOS or GOS-E between 3 and 6 months. The NOS-TBI demonstrated higher sensitivity to change, compared with the GOS (p<0.038) and GOS-E (p<0.016). In summary, the NOS-TBI demonstrated adequate concurrent and predictive validity as well as sensitivity to change, compared with gold-standard outcome measures. The NOS-TBI may enhance prediction of outcome in clinical practice and measurement of outcome in TBI research.

Very early hypothermia induction in patients with severe brain injury (the National Acute Brain Injury Study: Hypothermia II): a randomised trial.

BACKGROUND: The inconsistent effect of hypothermia treatment on severe brain injury in previous trials might be because hypothermia was induced too late after injury. We aimed to assess whether very early induction of hypothermia improves outcome in patients with severe brain injury. METHODS: The National Acute Brain Injury Study: Hypothermia II (NABIS: H II) was a randomised, multicentre clinical trial of patients with severe brain injury who were enrolled within 2·5 h of injury at six sites in the USA and Canada. Patients with non-penetrating brain injury who were 16-45 years old and were not responsive to instructions were randomly assigned (1:1) by a random number generator to hypothermia or normothermia. Patients randomly assigned to hypothermia were cooled to 35°C until their trauma assessment was completed. Patients who had none of a second set of exclusion criteria were either cooled to 33°C for 48 h and then gradually rewarmed or treated at normothermia, depending upon their initial treatment assignment. Investigators who assessed the outcome measures were masked to treatment allocation. The primary outcome was the Glasgow outcome scale score at 6 months. Analysis was by modified intention to treat. This trial is registered with ClinicalTrials.gov, NCT00178711. FINDINGS: Enrolment occurred from December, 2005, to June, 2009, when the trial was terminated for futility. Follow-up was from June, 2006, to December, 2009. 232 patients were initially randomised a mean of 1·6 h (SD 0·5) after injury: 119 to hypothermia and 113 to normothermia. 97 patients (52 in the hypothermia group and 45 in the normothermia group) did not meet any of the second set of exclusion criteria. The mean time to 35°C for the 52 patients in the hypothermia group was 2·6 h (SD 1·2) and to 33°C was 4·4 h (1·5). Outcome was poor (severe disability, vegetative state, or death) in 31 of 52 patients in the hypothermia group and 25 of 56 in the normothermia group (relative risk [RR] 1·08, 95% CI 0·76-1·53; p=0·67). 12 patients in the hypothermia group died compared with eight in the normothermia group (RR 1·30, 95% CI 0·58-2·52; p=0·52). INTERPRETATION: This trial did not confirm the utility of hypothermia as a primary neuroprotective strategy in patients with severe traumatic brain injury.

Multicenter trial of early hypothermia in severe brain injury.

The North American Brain Injury Study: Hypothermia IIR (NABIS:H IIR) is a randomized clinical trial designed to enroll 240 patients with severe brain injury between the ages of 16 and 45 years. The primary outcome measure is the dichotomized Glasgow Outcome Scale (GOS) at 6 months after injury. The study has the power to detect a 17.5% absolute difference in the percentage of patients with a good outcome with a power of 80%. All patients are randomized by waiver of consent unless family is immediately available. Enrollment is within 2.5 h of injury. Patients may be enrolled in the field by emergency medical services personnel affiliated with the study or by study personnel when the patient arrives at the emergency department. Patients who do not follow commands and have no exclusion criteria and who are enrolled in the hypothermia arm of the study are cooled to 35 degrees C as rapidly as possible by intravenous administration of up to 2 liters of chilled crystalloid. Those patients who meet the criteria for the second phase of the protocol (primarily a post-resuscitation GCS 3-8 without hypotension and without severe associated injuries) are cooled to 33 degrees C. Patients enrolled in the normothermia arm receive standard management at normothermia. As of December 2007, 74 patients had been randomized into phase II of the protocol. Patients in the hypothermia arm reached 35 degrees C in 2.7 +/- 1.1 (SD) h after injury and reached 33 degrees C at 4.4 +/- 1.5 h after injury.