The natural history of sleep disturbance among OEF/OIF veterans with TBI and PTSD and the role of proxy variables in its measurement

Abstract

ObjectiveSleep disturbance crosscuts post-traumatic stress disorder (PTSD) and traumatic brain injury (TBI). Though previous cross-sectional findings demonstrate a compounding effect of PTSD and TBI comorbidity, relatively little is known about the longitudinal trajectory of sleep-related complaints in veterans with TBI history and current PTSD symptoms. In this study, we explored patterns and predictors of sleep complaints in a sample of combat veterans with and without TBI and PTSD. MethodsSecondary analysis of data gathered during a longitudinal study of U.S. veterans of Operations Enduring and Iraqi Freedom (OEF/OIF) with and without TBI. Data from a subsample of 291 participants with sleep self-report data were analyzed using multinomial logistic regression logit testing and linear mixed models. ResultsOver an 18-month period, we observed an average 23–28% reduction in sleep symptoms in our sample as measured by two proxy scales, with the bulk of change (12–14% overall reduction) detected at the first six-month follow-up assessment. TBI history emerged, overall, as the most prominent predictor of worse general sleep symptoms, though baseline PTSD and pain status also demonstrated an association with worse sleep symptoms. ConclusionWhereas changes in PTSD symptoms over time were associated with worsening sleep symptoms, improvement in sleep reports was most consistently predicted by the passage of time. Our data also provide preliminary support for using three-to-four core items (i.e., trouble sleeping, changes in sleep, fatigue, and nightmares) to screen for sleep complaints in veterans with TBI and PTSD and/or track sleep-related outcomes.