Influence of Prior and Intercurrent Brain Injury on 5-Year Outcome Trajectories after Moderate to Severe Traumatic Brain Injury

Objective: To characterize the influence of additional (both prior and subsequent) traumatic brain injuries (TBIs) on recovery after a moderate to severe index TBI. Setting: Traumatic Brain Injury Model Systems centers. Participants: Persons with moderate to severe TBI (N = 5054) enrolled in the TBI Model Systems National Database with complete outcome data for the outcomes of interest at 1-, 2-, and 5-year follow-up. Design: Secondary analysis of a prospective longitudinal data set. Main Measures: Prior and intercurrent TBI from the Ohio State University TBI Identification Method (OSU TBI-ID), Disability Rating Scale (DRS), and Functional Independence Measure (FIM). Results: Prior moderate-severe TBIs significantly predicted overall level of functioning on the DRS, FIM Cognitive, and FIM Motor for participants with less severe index injuries. Moderate-severe intercurrent TBIs (TBIs subsequent to the index injury) were predictive of poorer functioning for both Index Severity groups, reflected in higher mean scores on the DRS in participants with less severe index injuries and lower mean Cognitive FIM in participants with more severe index injuries. Conclusion: Multiple brain injuries, particularly those of moderate or greater severity, have a significantly greater impact on patients' level of functioning compared with a single injury, but not the rate or shape of recovery.