Epidemiology of traumatic head injuries in Sweden during 2008-2022

Traumatic head injuries, including fractures and traumatic brain injuries (TBIs), are primarily caused by falls and road traffic accidents (RTAs). Since the introduction of the Vision Zero policy in Sweden in 1997, falls have overtaken RTAs as the main cause of traumatic head injuries. This study aimed to estimate national injury rates of fractures and TBIs in both inpatient and outpatient specialised care in Sweden from 2008 to 2022. Data from the Swedish National Patient Register from 2008 to 2022 were stratified by external cause, sex, age, and injury (fractures and TBIs). Changes over time were analysed using generalised estimating equations with a first-order autoregressive correlation structure. Holm-Bonferroni adjusted p-values were applied to account for multiple comparisons. Rates of traumatic head injuries, TBIs, and fractures declined for both sexes, with less pronounced decrease among women. Falls remain the primary cause of head injury with a minor decrease for men and no reduction for women from 2008 to 2022. Falls accounted for 62-67% of traumatic head injuries in women and 46-57% in men throughout the study period. Transport-related injuries remained below 20% for both sexes. While concussions and fractures declined overall, fracture rates among women remained stable. Subdural and subarachnoid haemorrhages (SDH and SAH) doubled in incidence between 2008 and 2022. Head injury rates were highest among individuals aged 85+, with SDH and SAH trends closely mirroring demographic shifts. Including outpatient care data improves the accuracy of head injury estimates, especially for concussions, which are often underreported in inpatient-only studies. The rising incidence of SDH and SAH along with an increase in head injuries among the elderly highlights the need for targeted prevention strategies. While Vision Zero has successfully reduced transport-related injuries, other efforts are needed to address fall-related head injuries.