Global, Regional, and National Burden of Head Injuries and Main Causes, 1990-2021: A Systematic Analysis of the Global Burden of Disease Study With Projections to 2050

BACKGROUND AND OBJECTIVES: We report the global, regional, and national burden of head injuries and their principal causes from 1990 to 2021, with projections to 2050. METHODS: In the Global Burden of Disease Study 2021, "head injuries" denotes the cause category "injuries to the head". We extracted age-standardized prevalence, incidence, and years lived with disability (YLDs), with absolute case counts and 95% uncertainty intervals, stratified by age, sex, year, country, and sociodemographic index; the etiological category "transport injuries" includes both motorized and nonmotorized modes. Temporal trends were assessed using the estimated annual percentage change, and projections to 2050 were generated with autoregressive integrated moving average models, with order selected by the Akaike information criterion and residual diagnostics. RESULTS: In 2021, head injuries accounted globally for an estimated 37.9 million prevalent cases, 20.8 million new cases, and 5.5 million YLDs. Compared with 1990, these absolute counts had risen by 54.4%, 22.6%, and 52.7%, respectively, reflecting population growth and aging. Over the same period, age-standardized rates (ASRs) declined by 16.5% for prevalence (536.7-448.0 per 100 000), 20.2% for incidence (324.4-259.0), and 16.2% for YLDs (77.3-64.8). Transport injuries were the leading etiological contributor to YLDs (20.7%), followed by falls (9.0%). The highest age-standardized burden was observed in high-middle sociodemographic index regions and in Europe, with older adults and males disproportionately affected. Autoregressive integrated moving average projections suggest a continued decline in ASRs through 2050. CONCLUSION: ASRs of head injury have declined globally between 1990 and 2021, yet absolute case numbers have continued to rise because gains in per-capita risk reduction have been outpaced by population growth and aging.