Due to copyright issues, an electronic copy of the thesis must be ordered from the faculty. For the faculty to have time to process the order, the order must be received by the faculty at the latest 2 days before the public defence. Orders received later than 2 days before the defence will not be processed. After the public defence, please address any inquiries regarding the thesis to the candidate.
Trial Lecture – time and place
See Trial Lecture.
Adjudication committee
- First opponent: Professor Niklas Marklund, Lund University, Sweden
- Second opponent: Professor Tor Ingebrigtsen, UiT - The Arctic University of Norway, Tromsø
- Third member and chair of the evaluation committee: Associate Professor Grethe Månum, University of Oslo
Chair of the Defence
Professor Leiv Arne Rosseland, University of Oslo
Principal Supervisor
Jon Ramm-Pettersen, Oslo University Hospital
Summary
Our clinical impression was that the magnitude of bicycle-related injuries admitted to Oslo University Hospital (OUH) was increasing and far exceeded the numbers in the official statistics provided by Statistics Norway.
Therefore, we used retrospective cohort studies based on the OUH Trauma Registry to describe the number, crash mechanisms, severity of injury, and assessed the protective effects of helmet wearing on head injuries in bicyclists. In addition, we describe bicycle-related cervical spine injuries (CSIs) in a cohort study based on the quality control database for all CSIs in the South-Eastern region of Norway.
The annual number of hospitalized bicyclists more than doubled during the study period, and increased from 79 patients per year in 2005 to 184 patients in 2016. The typical hospitalized bicyclist was young and healthy, while the most common mechanism of injury was a single-bicycle crash (68%). According to the Injury Severity Score, 63% of patients sustained a serious injury.
The annual rate of helmet use increased from 39% in 2005 to 48% in 2016. Helmeted bicyclists were older and crashed less often during the night than non-helmeted bicyclists. Helmeted bicyclists had a statistically significant 71% odds reduction for serious head injury, and 64% odds reduction for undergoing cranial neurosurgery. Furthermore, helmeted bicyclists had a non-significant 50% odds reduction for mortality (p=0.09).
Bicycle crashes were the second most common cause of CSIs after falls and accounted for 12% of all CSIs. The incidence of bicycle-related CSIs was 1.7/100,000/year. Multivariate analyses revealed a significantly increased risk of occipital condyle fractures for bicyclists compared with non-bicyclists. Hence, the occipital condyle fracture appears to be a typical “bicyclist fracture”, which clinicians should be aware of.
We believe that this doctoral thesis may aid in ensuring more targeted injury prevention programs for bicyclists.
Additional information
Contact the research support staff.