Factors Associated with Word Memory Test Performance in Persons with Medically Documented Traumatic Brain Injury

(1) To examine the rate of poor performance validity in a large, multicenter, prospectively accrued cohort of community dwelling persons with medically documented traumatic brain injury (TBI), (2) to identify factors associated with Word Memory Test (WMT) performance in persons with TBI.

This was a prospective cohort, observational study of 491 persons with medically documented TBI. Participants were administered a battery of cognitive tests, questionnaires on emotional distress and post-concussive symptoms, and a performance validity test (WMT). Additional data were collected by interview and review of medical records.

One hundred and seventeen participants showed poor performance validity using the standard cutoff. Variable cluster analysis was conducted as a data reduction strategy. Findings revealed that the 10 cognitive tests and questionnaires could be summarized as 4 indices of emotional distress, speed of cognitive processing, verbal memory, and verbal fluency. Regression models revealed that verbal memory, emotional distress, age, and injury severity (time to follow commands) made unique contribution to prediction of poor performance validity.

Poor performance validity was common in a research sample of persons with medically documented TBI who were not evaluated in conjunction with litigation, compensation claims, or current report of symptoms. Poor performance validity was associated with poor performance on cognitive tests, greater emotional distress, lower injury severity, and greater age. Many participants expected to have residual deficits based on initial injury severity showed poor performance validity.