Measuring recovery in new learning and memory following traumatic brain injury: A mixed-effects modeling approach

Patterns of recovery from traumatic brain injury ( TBI) vary greatly across individuals. Using archival data from the Traumatic Brain Injury Model Systems, recovery of memory following TBI as measured by scores on the Rey Auditory Verbal Learning Test ( RAVLT) through 5 years postinjury was examined via mixed-effects modeling. Individual-level variables of age and posttraumatic amnesia duration were significant predictors of 1-year RAVLT total score. None of the variables examined predicted the trajectory of memory recovery after 1 year. Mixed-effects analyses can be helpful in determining the effect of intervention while allowing for missing data across time points.