Reconsidering cognitive outcome one year after mild traumatic brain injury: Secondary analysis of TRACK-TBI data

Objective: Uncomplicated mild traumatic brain injury (mTBI) is time-limited with a well-documented natural course of recovery. Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) findings indicated poor cognitive outcomes 1 year after mTBI. We examined TRACK-TBI data with consideration of neuroimaging and performance validity. Method: TRACK-TBI data were obtained from the Federal Interagency Traumatic Brain Injury Research Informatics System. The sample (N = 571) included 439 cases with mTBI history and 132 orthopedic controls. One-year cognitive outcome measures included Auditory Verbal Learning Test total immediate (TOT) and delayed recall (DR), Trail Making Test (-A and -B), and WAIS-IV Processing Speed Index (PSI). Rates of low scores were examined using previously reported cutoffs and across all tests in the study. Linear regression was used to examine predictors of cognitive outcomes. Results: Group differences at 1-year follow-up were minimal. Although control participants scored significantly higher on TOT and DR, cognitive ability was within normal limits on all tests in both groups. Low score rates were significantly different between groups on TOT and DR. History of mTBI did not significantly contribute to prediction of overall cognitive ability. Conclusions: Uncomplicated mTBI is not associated with long-term cognitive impairment after accounting for performance validity. Findings highlight the importance of distinguishing complicated and uncomplicated mTBI in research and clinical settings. Future studies might examine psychological and functional outcomes with a similar design.