Outcome assessment in traumatic brain injury clinical trials and prognostic studies.

Large numbers of investigations have sought to evaluate prediction of outcome after traumatic brain injury (TBI) and the effectiveness of interventions designed to address post-TBI deficits. Unfortunately, failure to attend to key issues in experimental design regarding outcome assessment has limited the utility of these investigations. Increased attention to 5 issues in outcome assessment will increase the evidence base for TBI prognosis and treatment and increase the relevance of findings to end users of research such as other investigators, rehabilitation providers, policy makers, persons with TBI, and family members of persons with TBI. These 5 issues are (1) masking of outcome examiners, (2) retention of study participants, (3) use of surrogate informants to capture data from a wider range of study participants, (4) relevance of study outcomes to stakeholders, and (5) cultural considerations in outcome assessment.