A Retrospective Study of Demographic, Medical, and Psychological Predictors of Readiness in Service Members With Mild Traumatic Brain Injury.

Introduction: Given the significant number of service members who have incurred mild traumatic brain injury (TBI) over the past two decades, this study was completed to determine the relative contribution of demographic, TBI-related, and psychological factors that predict the readiness of service members with primarily mild TBI.

Methods And Materials: This retrospective study included 141 service members who were evaluated at an outpatient military TBI rehabilitation clinic. Information regarding demographics, TBI-related variables, and psychological factors was collected and entered into hierarchical multinomial logistic regressions to predict military work status. Demographic predictor variables included age, race, gender, rank, service branch; TBI-specific variables including time since injury and neuropsychological variables (i.e., Wechsler Adult Intelligence Scale-IV (WAIS-IV) Full Scale Intelligence Quotient (FSIQ) and Processing Speed Indices; California Verbal Learning Test-IV total recall t-score); and psychiatric variables including concomitant psychiatric diagnoses and Personality Assessment Inventory indices. The outcome variable was the service member's military work status (i.e., return to duty (RTD); Medical Evaluation Board-disabled (MEB); retired) at time of discharge from the TBI clinic.

Results: Statistical analyses indicated that the total model predicted 31% of the variance in work status, with demographics predicting 16% of the variance, concomitant psychiatric diagnoses and WAIS-IV FSIQ predicting an additional 12%, and subjective somatic/psychological distress (Personality Assessment Inventory indices) predicting an additional 3%. Regarding the primary groups of interest (i.e., RTD vs. MEB), stepwise regressions indicated that those who RTD have higher intelligence and report less physical/psychological distress than the disabled group.

Conclusions: In general, those service members who were able to RTD versus those who were classified as disabled (MEB) were of higher IQ and reported less somatic/psychological distress. Of note, traditional indices of TBI severity did not predict the ability of the sample to RTD. The results suggest the importance of treating psychological conditions and identifying possible indicators of resilience (e.g., higher intelligence) to increase the readiness of service members with mild TBI.