Abstract

Context: Large-scale baseline cognitive assessment for individuals at risk for concussion is a common part of the protocol for concussion-surveillance programs, particularly in sports. Baseline cognitive testing is also being conducted in US military service members before deployment. Recently, the incremental validity of large-scale baseline cognitive assessment has been questioned. Objective: To examine the added value of baseline cognitive testing in computer-based neuropsychological assessment by comparing 2 methods of classifying atypical performance in a presumed healthy sample. Design: Cross-sectional study. Setting: Military base. Patients or Other Participants: Military service members who took the Automated Neuropsychological Assessment Matrix (ANAM) before and after deployment (n = 8002). Main Outcome Measure(s): Rates of atypical performance in this healthy, active-duty sample were determined first by comparing postdeployment scores with a military normative database and then with each individual's personal baseline performance using a reliable change index. Results: Overall rates of atypical performance were comparable across these 2 methods. However, these methods were highly discordant in terms of which individuals were classified as atypical. When norm-referenced methods were used, 2.6% of individuals classified as normal actually demonstrated declines from baseline. Further, 65.7% of individuals classified as atypical using norm-referenced scores showed no change from baseline (ie, potential false-positive findings). Conclusions: Knowing an individual's baseline performance is important for minimizing potential false-positive errors and reducing the risks and stresses of misdiagnosis. Verf.-Referat