Influence of Prior and Intercurrent Brain Injury on 5-Year Outcome Trajectories After Moderate to Severe Traumatic Brain Injury.

The study observed associations after injury history; it did not assign injuries, so it cannot prove that prior or later TBI caused the worse outcomes. Only participants with complete outcome data at all three follow-up points were included, and those lost to follow-up were older, had more severe index injuries, and were more likely to be non-white, male, separated or widowed, or have a state payor. The outcome measures may not detect subtle effects of mild TBI or additional injuries in people with very severe index injuries. The models were trimmed to significant predictors, which increases the chance that some findings reflect chance. The database did not capture rehabilitation services after inpatient discharge, so later therapy could have affected outcomes in unknown ways. There were only three follow-up points, which limits how well the study could describe recovery trajectories.

The paper lists research support from NIH and U.S. government sources. No author conflict-of-interest statement is included.

Do not conclude that any head injury history worsens long-term recovery. Mild prior and intercurrent TBIs were not significant predictors, and prior TBI did not change the recovery course.