The Epidemiology of Moderate and Severe Traumatic Brain Injury in Central Norway.

INTRODUCTION: Few studies account for prehospital deaths when estimating incidence and mortality rates of moderate and severe traumatic brain injury (msTBI). In a population-based study, covering both urban and rural areas, including also prehospital deaths, the aim was to estimate incidence and mortality rates of msTBI. Further, we studied the 30-day and 6-month case-fatality proportion of severe TBI in relation to age. METHODS: All patients aged ≥17 years who sustained an msTBI in Central Norway were identified by three sources: (1) the regional trauma center, (2) the general hospitals, and (3) the Norwegian Cause of Death Registry. Incidence and mortality rates were standardized according to the World Health Organization's world standard population. Case-fatality proportions were calculated by the number of deaths from severe TBI at 30 days and 6 months, divided by all patients with severe TBI. RESULTS: The overall incidence rates of moderate and severe TBI were 4.9 and 6.7 per 100,000 person-years, respectively, increasing from age 70 years. The overall mortality rate was 3.4 per 100,000 person-years, also increasing from age 70 years. Incidence and mortality rates were highest in men. The case-fatality proportion in people with severe TBI was 49% in people aged 60-69 years and 81% in people aged 70-79 years. CONCLUSION: The overall incidence and mortality rates for msTBI in Central Norway were low but increased from age 70 years, and among those ≥80 years of age with severe TBI, nearly all died. Overall estimates are strongly influenced by high incidence and mortality rates in the elderly, and studies should therefore report age-specific estimates, for better comparison of incidence and mortality rates.

Moderate and severe traumatic brain injury in general hospitals: a ten-year population-based retrospective cohort study in central Norway.

BACKGROUND: Patients with moderate and severe traumatic brain injury (TBI) are admitted to general hospitals (GHs) without neurosurgical services, but few studies have addressed the management of these patients. This study aimed to describe these patients, the rate of and reasons for managing patients entirely at the GH, and differences between patients managed entirely at the GH (GH group) and patients transferred to the regional trauma centre (RTC group). We specifically examined the characteristics of elderly patients. METHODS: Patients with moderate (Glasgow Coma Scale score 9-13) and severe (score ≤ 8) TBIs who were admitted to one of the seven GHs without neurosurgical services in central Norway between 01.10.2004 and 01.10.2014 were retrospectively identified. Demographic, injury-related and outcome data were collected from medical records. Head CT scans were reviewed. RESULTS: Among 274 patients admitted to GHs, 137 (50%) were in the GH group. The transferral rate was 58% for severe TBI and 40% for moderate TBI. Compared to the RTC group, patients in the GH group were older (median age: 78 years vs. 54 years, p < 0.001), more often had a preinjury disability (50% vs. 39%, p = 0.037), and more often had moderate TBI (52% vs. 35%, p = 0.005). The six-month case fatality rate was low (8%) in the GH group when transferral was considered unnecessary due to a low risk of further deterioration and high (90%, median age: 87 years) when neurosurgical intervention was considered nonbeneficial. Only 16% of patients ≥ 80 years old were transferred to the RTC. For this age group, the in-hospital case fatality rate was 67% in the GH group and 36% in the RTC group and 84% and 73%, respectively, at 6 months. CONCLUSIONS: Half of the patients were managed entirely at a GH, and these were mainly patients considered to have a low risk of further deterioration, patients with moderate TBI, and elderly patients. Less than two of ten patients ≥ 80 years old were transferred, and survival was poor regardless of the transferral status.