Outcome measures for clinical trials in neurotrauma.

Under the auspices of the American Brain Injury Consortium and the Joint Section of Neurotrauma and Critical Care of the American Association of Neurological Surgeons, the authors have reviewed and formulated opinions based on the evidence on protocol design and the outcome measures used for clinical trials in patients with a severe or moderate traumatic brain injury (TBI). First, in view of the heterogeneity of the population under study, the authors suggest that block randomization and stratification should always be used in the design of neurotrauma trials. Second, although the Glasgow Outcome Scale (GOS) remains the most widely used and accepted instrument for TBI trials, the authors believe the eight-point expanded scale that has recently been designed will ultimately provide greater discrimination, and narrower categories and will ultimately prove superior for detecting more subtle changes in outcome. Furthermore, the authors recommend, in view of the profound cognitive impairment in survivors of TBI, that neuropsychological tests be explored further as an adjunct to the GOS. Future research should focus on the development of more sensitive and specific surrogate outcome measures such as magnetic resonance imaging, neurochemical, neuropsychological, and quality of life measures in order to detect a neuroprotective effect in patients with TBI.