Abstract
Objective
This study examined whether practice effects caused by repeated exposure to test materials during serial assessment significantly impacts the performance of adults with chronic severe traumatic brain injury (sTBI), given the severe memory impairment typical of this population. This study sought to describe the pattern of practice effects on repeat neuropsychological testing for this population. It was hypothesized that practice effects would be diminished for individuals with chronic sTBI.
Method
This study utilized longitudinal archival data collected as part of an annual neuropsychological assessment battery administered to 43 individuals receiving post-acute rehabilitation services at a structured multisite day treatment program. Each participant was tested at two time points which differed by an average of 13 months. The battery consisted of the Texas Functional Living Scale (TFLS), Trail Making Test (TMT), Brief Mood Survey, Neuropsychological Assessment Battery (NAB) Screening Module (NAB-SN), and Judgment subtest from the NAB Executive Functions Module (NAB Judgment).
Results
Practice effects were determined based on reliable improvement (p < .05) in scores across test administrations. A Reliable Change Index (RCI) was calculated for each test based on the method proposed by Jacobson and Truax (1991). Results revealed reliable improvements in performance for the NAB-SN Attention domain (RCI = 3.69), NAB Judgment subtest (RCI = 10.14), and TFLS Total Score (RCI = 4.38).
Conclusion
This study indicates that adults with chronic sTBI demonstrate significant practice effects primarily on measures associated with functional living skills. These findings suggest that repeat testing in this population may be less susceptible to the influence of practice effects.
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