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Using Hospital Data to Enhance Traffic Accident Prevention in Denmark

Recent research from the University of Southern Denmark and Odense University Hospital reveals that traffic accidents are significantly underreported to the police, creating challenges for preventive measures

By Nana Olejank Hansen, , 5/8/2024

The hospitals' data sets contain larger numbers, whereas the police data are more detailed due to investigation at the site of the incident and the need to serve as evidence in a court case.

However, the Traffic Safety Commission relies solely on police data for traffic accident prevention, while hospital data has been considered supplementary. Perhaps, it should be the other way around. Both the police and hospitals record factors such as the types of vehicles involved, the number of people, and the severity of injuries. Hospitals, however, encounter far more cases.

Professor Jens Lauritsen, Department of Clinical Research, SDU, and Kristian Kjærgaard, MD, conducted a large study that shows strong alignment between the data registered by the police and the data collected at hospitals. They have demonstrated a 93% agreement between hospital data and police data. The key difference is that hospitals have recorded not only a greater number of cases than the police but have also done so with greater accuracy.

More Accurate Injury Assessment

-We encounter 6 to 10 times more cases than the police, Moreover, we assess the severity of accidents based on medical evaluation, which is more precise, says Jens Lauritsen, Professor at the Department of Clinical Research, SDU, and continues:

-It is no surprise that doctors can assess the severity of injuries. Now, it has also been shown that it is possible to document the mode of transport, the accident situation, and the role of the individual involved. This is achieved through detailed and systematic recording in the emergency department.

Jens Lauritsen recommends starting preventive planning based on hospital data ass well as police data.

Classifications system for the severity of personal injuries

The Department of Orthopaedic Surgery has developed a classification system for the severity of personal injuries from traffic accidents. This system, grounded in medical analysis, provides a reliable indicator of injury severity based on diagnoses.

The police are not always involved

One reason hospitals record more incidents than the police are that police reports cover only 10-15% of the roughly 52,000 annual traffic accidents. This encompasses drivers, cyclists, pedestrians struck by vehicles, and other road-related incidents.

-The police are not always involved; often, individuals manage the situation themselves and proceed directly to the hospital," explains Jens Lauritsen.

Data is Crucial for Preventing Further Accidents

Having the right data can make a difference. For example, the police can target efforts through traffic campaigns, focusing on intersections with high-risk levels.

-We have had a strong partnership with the Funen Police for many years. They utilise the Accident Analysis Group's data collected in the Emergency Department when planning campaigns. They focus on areas with the highest accident rates, allowing them to be strategically present. This approach could be implemented nationwide, explains Jens Lauritsen.

Hospitals Provides Highly Accurate Data

The study encompasses all individuals who presented at the Emergency Department of Odense University Hospital due to traffic accidents from 2015 to 2021. These patients were treated by doctors from the Department of Orthopaedic Surgery, in collaboration with emergency department staff and secretaries. The information recorded by the secretaries was compared with police data.

By using the Civil Registration Number and the date of the incident, the data could be accurately compared.

-We have already demonstrated that our hospital data is highly accurate. A similar analysis is being planned in collaboration with Statistics Denmark. We need to ensure the same level of thoroughness and accuracy across all emergency departments nationwide if the Road Safety Commission is to use hospital data, says Jens Lauritsen.

What data is recorded?

Several principal categories are monitored, including:

  • Location of injury
  • Activity - specifically, transportation
  • Mode of transport
  • Involved parties
  • Role of traffic participants
  • Safety equipment utilised - for instance seat belts and helmets

Each primary category encompasses further subcategories that detail the specifics of the incident.

About the study

  • The study was conducted by Jens Lauritsen alongside Kristian Kjærgaard, a doctor and PhD from SDU.
  • Data were gathered on Funen from 2015 to 2021. Funen has approximately 470,000 residents.
  • Data about injuries from traffic accidents were collected at the Emergency Department of Odense University Hospital.
  • A total of 21,562 injuries were recorded, of which 5,176 were serious. Only 10% of minor injuries and 15% of more severe injuries were known to the police. Typically, injuries involving children, cyclists, or "vulnerable road users" were not recorded by the police.
  • Both the accidents and the extent of injuries were systematically registered at the Emergency Department using a special coding card—a form that allows for recording both categories and subcategories such as mode of transport, type of injury, and geography.
  • All data are analysed and reported in anonymised form to ensure that no individual can be identified.
Meet the researcher

Jens Lauritsen is a professor at the Research Unit for Orthopaedic Surgery and a senior consultant with the Accident Analysis Group. The Accident Analysis Group has been engaged in documenting and analysing accidents, including traffic accidents, since the 1970s. Jens Lauritsen has been involved in this field since the 1980s, when his licentiate thesis established the coverage level for the group's work.


Meet the researcher

Kristian Kjærgaard is a medical doctor and PhD who has been associated with the Accident Analysis Group as a research assistant since 2021.


Read the study

The study: "Variation in traffic injury settings—same implication of hospital and police-based traffic injury data?" is published in Journal of Transport & Health j.jth.2024.101782

Editing was completed: 08.05.2024