Factors associated with neurocognitive performance in OIF/OEF servicemembers with postconcussive complaints in postdeployment clinical settings.

Cognitive difficulties are frequently reported by Operation Enduring Freedom /Operation Iraqi Freedom military personnel who sustained mild traumatic brain injuries (TBIs). The current study examined several potential factors that may contribute to self-reported cognitive difficulties in postdeployment clinical settings. Eighty-four subjects who sustained a mild or moderate TBI and reported cognitive difficulties underwent neurocognitive testing. Multiple regression analyses were used to determine the amount of variance in neurocognitive performance accounted for by the predictor variables (demographic, mechanism of injury, time since injury, headache severity, combat stress, postconcussive complaints, and effort/performance validity). The predictor variables collectively accounted for 51.7% of the variance in cognitive performance (F (8,72) = 11/99, p < 0.001). The most potent predictor of cognitive functioning was performance validity/effort, which uniquely accounted for 16.3% of the variance (p < 0.01). Self-reported symptom severity, including postconcussive complaints, combat stress, and headache intensity, accounted for 7.2% of the variance (p < 0.05). Demographic factors and injury characteristics, such as time since injury and mechanism of injury, were not significant predictive factors of cognitive performance. The findings of the current study underscore the need to include measurement of effort as part of neurocognitive evaluation in postdeployment settings when evaluating cognitive complaints associated with mild TBI.