Incidence of hospital-admitted severe traumatic brain injury and in-hospital fatality in Norway: a national cohort study.

AIMS The aims of this study were to assess the incidence of hospital-admitted severe traumatic brain injury (TBI) in the adult population in Norway, and to determine whether there were differences in the epidemiological characteristics of severe TBI between rural and urban regions. METHODS A prospective population-based study on adults with severe TBI admitted to the Norwegian Trauma Referral Centres during the 2-year period (2009-2010). The electronic patient register was searched weekly for ICD-10 diagnoses of intracranial injuries (S06.0-S06.9) to identify patients. Severe TBI was defined as lowest unsedated Glasgow Coma Scale Score ≤8 during the first 24 h after injury. RESULTS The annual age-adjusted incidence was estimated at 5.2/100,000 in 2009 and 4.1/100,000 in 2010. The highest frequency of hospitalized patients was found among the youngest and the oldest age groups. The most common causes of injury were falls and transport accidents. The highest in-hospital case-fatality rate was found among the oldest patients. There were consistent epidemiological characteristics of severe TBI from both rural and urban regions. CONCLUSIONS The incidence of hospital-admitted patients with severe TBI in this national study supports the declining incidence of TBI reported internationally. No major differences were found in epidemiological characteristics between the urban and rural parts of Norway.