Traumatic brain injuries in Geneva: the geography of risk

Traumatic brain injuries in Geneva: the geography of risk

Traumatic brain injuries are not evenly distributed across the Canton of Geneva. They tend to cluster in specific locations, at certain times of the year, and within particular population groups, with different risk profiles observed among older adults and working-age individuals.

This is the main finding of a population-based study conducted by Anabelle Ayma and Quitterie Legrand, two EPFL students, together with a team of researchers from EPFL and the HUG NeuroCentre, including Stéphane Joost (GIRAPH Laboratory of the Population Epidemiology Unit at HUG and the GEOME Lab at EPFL), Philippe Voruz (GEOME Lab and neuropsychologist at HUG), Giannina Iannotti, PhD-eMBA, Head of the NeuroCentre, and Professor Karl Schaller, Head of the NeuroCentre and Chief Physician of the Department of Neurosurgery at HUG. The study was published in the American Journal of Public Health.

The research team analyzed 1,071 cases of traumatic brain injury (TBI) requiring hospitalization in Geneva between 2012 and 2024 and compared them with a synthetic reference population of 10,000 residents reflecting the demographic structure of the canton. By combining spatial, temporal, and multivariate analyses, the team investigated where and when these injuries occur and how clinical, demographic, and socioeconomic factors interact.

Key findings

  1. Four significant spatial clusters were identified 
    Among adults aged 60 years and older, traumatic brain injuries were concentrated in central Geneva and the Dardagny region, areas characterized by a high proportion of older residents and the presence of long-term care facilities. For working-age adults (18–59 years), clusters were primarily located in the western and southern parts of the canton. These distributions did not overlap, highlighting the existence of age-specific risk environments.
     
  2. Temporal patterns vary by age group
    Hospitalizations among older adults peaked in autumn and at the beginning of the week, a pattern consistent with the influence of environmental factors such as reduced daylight or slippery surfaces, as well as certain lifestyle habits. In contrast, hospitalizations among working-age adults were distributed more evenly throughout the week.
     
  3. Ten distinct patient profiles were identified
    By combining demographic, clinical, and socioeconomic data, the researchers identified different trajectories, ranging from older men living alone who experienced longer hospital stays and were less likely to return directly home, to women living in suburban areas with high educational attainment but facing greater socioeconomic vulnerability. Overall, the findings suggest that outcomes following a traumatic brain injury are influenced not only by the characteristics of the injury itself, but also by the interaction between age, social conditions, and living environment.

This study demonstrates how routinely collected hospital data can provide a clearer understanding of the spatial and temporal distribution of traumatic brain injury risk. By identifying locations and periods with the highest incidence, such analyses can help guide prevention strategies, enhance the safety of older adults, adapt healthcare services, and support more equitable public health planning.

The study also underscores the importance of an interdisciplinary approach at the intersection of epidemiology, neuroscience, and neuropsychology. Integrating clinical, spatial, and temporal data opens the door to new approaches in neurogeography and neuroepidemiology, “at the heart of the NeuroGIRAPH approach,” as Giannina Iannotti points out.

Last update : 03/09/2026