Changes in neuropsychological performance after traumatic brain injury from inpatient rehabilitation to 1-year follow-up in predicting 2-year functional outcomes.

The present study explored the predictive value of interval change in neuropsychological performance at three time-points following moderate-to-severe TBI (inpatient rehabilitation, 1-year, and 2-year follow-up) on functional outcome measures collected at 2-year follow-up. Symmetrized percent change scores were calculated and used to predict scores on functional measures using linear regression while controlling for age and injury severity. Results showed that change in performance from inpatient to 1-year on total list learning (CVLT-II or RAVLT) and oral SDMT significantly predicted 2-year ratings of functional status. By comparison, most neuropsychological measures taken at 1-year follow-up also accounted for unique variance in 2-year functional outcomes. These results indicate that changes in learning and processing speed during the first year of recovery are sensitive indicators when predicting long-term disability and degree of functional independence, though absolute performance at 1 year is also highly associated with functional outcome at 2 years post-injury.