Thirty-Five Years of Change: Shifts in Demographic and Injury Profiles of Traumatic Brain Injury Cases Enrolled in the Traumatic Brain Injury Model Systems (1988–2024): A NIDILRR TBIMS National Database Study

OBJECTIVE: To characterize long-term changes in demographic and injury profiles among individuals with traumatic brain injury (TBI) admitted to inpatient rehabilitation and enrolled in the TBI Model Systems (TBIMS) National Database (NDB). SETTING: Twenty-three inpatient rehabilitation hospitals participating in the TBIMS program. PARTICIPANTS: 20 990 persons 16 years and older with TBI who received inpatient rehabilitation and enrolled in the TBIMS NDB between 1988 and 2024. DESIGN: Repeated cross-sectional analysis of a prospectively collected longitudinal database across 7 admission cohorts. MAIN MEASURES: Sociodemographic characteristics (age, sex, race/ethnicity, education, employment, marital status, payor source) and injury characteristics (etiology, Glasgow Coma Scale [GCS], command following, post-traumatic amnesia [PTA], Functional Independence Measure [FIM], acute and rehabilitation length of stay [LOS]). RESULTS: Mean age at injury increased from 34.6 years in 1988-1994 to 48.4 in 2020-2024, accompanied by a rise in fall-related injuries, a decline in violence-related injuries, and a shift in vehicular injuries from earlier increases to more recent declines. The proportion of participants who were retired increased substantially, while the proportion who were unemployed declined. Racial/ethnic minority representation declined from 1988-1994 to 2000-2004 and then increased through 2020-2024, particularly among younger individuals. Medicare coverage increased while Medicaid coverage declined. The proportion of participants with complicated mild TBI increased while moderate and severe classifications declined, accompanied by shorter time to command following and PTA duration. Despite these indicators of decreasing injury severity, FIM motor scores at rehabilitation admission declined modestly. Acute LOS declined slightly while rehabilitation LOS declined substantially. CONCLUSIONS: Over the past 35 years, the TBIMS population has shifted toward an older cohort, accompanied by changes in demographic patterns associated with aging, mechanisms of injury, functional profiles, payor source, and lengths of stay. These changes should be considered when interpreting TBIMS longitudinal outcomes, evaluating representativeness, translating prior research findings to contemporary populations, and planning rehabilitation services for individuals with TBI.