The Influence of Age on the Outcomes of Traumatic Brain Injury: Findings from a Japanese Nationwide Survey (J-ASPECT Study-Traumatic Brain Injury)

Background: The epidemiology of patients with traumatic brain injury (TBI) has changed dramatically over recent decades as a result of rapid advances in aging societies. We assessed the influence of age on outcomes of patients with TBI and sought to identify prognostic factors for in-hospital mortality of TBI among elderly patients. Methods: Using a nationwide database, we analyzed data from 5651 patients with TBI. Univariate analysis was conducted to compare patient demographics, neurologic status on admission, radiologic findings, systemic complication rates, length of hospital stay, in-hospital mortality, and home discharge rates between elderly and nonelderly groups. Multivariable analysis was conducted to determine prognostic factors for in-hospital mortality among elderly patients. Results: Overall in-hospital mortality was significantly higher in elderly patients (12.8% vs. 19.3%; P < 0.001). In-hospital mortality of elderly patients with mild TBI increased significantly at >7 days after admission, whereas that of elderly patients with moderate or severe TBI was significantly higher immediately after admission. Age (odds ratio [OR], 1.62; P = 0.024), male sex (OR, 1.30; P = 0.004), Japan Coma Scale score on admission (OR, 5.95, P < 0.001), and incidence of acute subdural hematoma (OR, 1.89; P < 0.001) were associated with in-hospital mortality in elderly patients with TBI. Conclusions: Elderly patients with TBI showed significantly higher in-hospital mortality. Delayed increases in in-hospital mortality were observed among elderly patients with mild TBI. Level of consciousness on admission was the strongest predictor of in-hospital mortality among elderly patients.