Psychometric Investigation of the Abbreviated Concussion Symptom Inventory in a Sample of U.S. Marines Returning from Combat

This study describes the psychometric investigation of an 11-item symptom checklist, the Abbreviated Concussion Symptom Inventory (ACSI). The ACSI is a dichotomously scored list of postconcussive symptoms associated with mild traumatic brain injury. The ACSI was administered to Marines (N = 1,435) within the 1st month of their return from combat deployments to Afghanistan. Psychometric analyses based upon nonparametric item response theory supported scoring the ACSI via simple summation of symptom endorsements; doing so produced a total score with good reliability (α = .802). Total scores were also found to significantly differentiate between different levels of head injury complexity during deployment, F(3, 1,431) = 100.75, p < .001. The findings support the use of the ASCI in research settings requiring a psychometrically reliable measure of postconcussion symptoms.