Background: Traumatic brain injury (TBI) is a major cause of morbidity and mortality. However, it remains undetermined whether long-term outcomes after TBI have improved over the past two decades.
Methods: We conducted a retrospective analysis of consecutive TBI patients admitted to an academic neurosurgical ICU during 1999-2015. Primary outcomes of interest were 6-month all-cause mortality (available for all patients) and 6-month Glasgow Outcome Scale (GOS, available from 2005 onwards). GOS was dichotomized to favourable and unfavourable functional outcome. Temporal changes in outcome were assessed using multivariate logistic regression analysis, adjusting for age, sex, GCS motor score, pupillary light responsiveness, Marshall CT classification and major extracranial injury.
Results: Altogether, 3193 patients were included. During the study period, patient age and admission Glasgow Coma Scale score increased, while the overall TBI severity did not change. Overall unadjusted 6-month mortality was 25% and overall unadjusted unfavourable outcome (2005-2015) was 44%. There was no reduction in the adjusted odds of 6-month mortality (OR 0.98; 95% CI 0.96-1.00), but the adjusted odds of favourable functional outcome significantly increased (OR 1.08; 95% CI 1.04-1.11). Subgroup analysis showed outcome improvements only in specific subgroups (conservatively treated patients, moderate-to-severe TBI patients, middle-aged patients).
Conclusions: During the past two decades, mortality after significant TBI has remained largely unchanged, but the odds of favourable functional outcome have increased significantly in specific subgroups, implying an improvement in quality of care. These developments have been paralleled by notable changes in patient characteristics, emphasizing the importance of continuous epidemiological monitoring.
Keywords: Epidemiology; Mortality; Outcome; Traumatic brain injury.