Utility of the Mild Brain Injury Atypical Symptoms Scale as a Screening Measure for Symptom Over-Reporting in Operation Enduring Freedom/Operation Iraqi Freedom Service Members with Post-Concussive Complaints

Evaluation of post-deployment conditions such as post-concussive syndrome (PCS) and posttraumatic stress disorder (PTSD) frequently relies upon brief, self-report checklists which are face valid and highly susceptible to potential symptom validity issues such as symptom exaggeration. We investigated the psychometric prope1rties of a 5-item measure of symptom exaggeration (mild brain injury atypical symptoms [mBIAS] scale) embedded in commonly used PCS and PTSD screening instruments in a sample of 403 patients seen in a brain injury clinic at a large military medical center. Exploratory factor analysis, examining measures of posttraumatic stress, post-concussive symptoms, and symptom over-reporting revealed a 6-factor model with the mBIAS scale items representing a unique factor. Analysis of psychometric properties demonstrated that a score of 8 on the mBIAS was optimal for the detection of symptom over-reporting (sensitivity = 0.94, specificity = 0.92) and appears to be the most favorable cut score for interpretive use. The findings provide a strong initial support for the use of the mBIAS in post-deployment populations.