Global, Regional, and National Burden of Traumatic Brain Injury, 1990–2021: A Systematic Analysis for the Global Burden of Disease Study 2021

Traumatic brain injury (TBI) is a major global health concern, contributing substantially to mortality and disability. While previous studies have reported the global and regional burden of TBI, few have explored its long-term trends, cause-specific burden, sociodemographic disparities, and future projections in a comprehensive framework. To address this gap, we conducted a retrospective analysis using the Global Burden of Disease 2021 data to estimate TBI incidence, prevalence, and years lived with disability across sex, age, and Sociodemographic Index (SDI) quintiles. We used average annual percent change (AAPC) to evaluate temporal trends from 1990 to 2021 and applied Spearman's correlation to examine the association between age-standardized incidence rate (ASIR) and SDI. Projections of future trends were made using an autoregressive integrated moving average model. The results revealed that global TBI cases increased from 17.0 million in 1990 to 20.8 million in 2021, although the global ASIR decreased from 324.43 to 259.02 per 100,000, with an AAPC of -0.80%. The age-standardized prevalence rate (ASPR) also declined in high SDI locations, from 539.7 to 425.9 per 100,000 (AAPC: -0.76%), with similar declines observed in high-middle SDI locations. Southern Sub-Saharan Africa showed the largest reductions, whereas Oceania experienced a slight increase in ASIR, largely driven by falls and road injuries, with notable gender-specific patterns. By 2031, TBI incidence rates are projected to decline for both sexes, with falls remaining stable and road injuries decreasing. While the ASIR and ASPR of TBI have decreased, the absolute number of cases has risen, underscoring the need for public health interventions that consider regional differences in TBI trends and causes in order to effectively reduce the burden.