Older Adults with Traumatic Brain Injury in the Most Aged and Most Rapidly Aging Country: An Analysis of the Nationwide Trauma Registry of Japan

Abstract

Despite the increasing numbers of older adults with traumatic brain injury (TBI), minimal data are available to support the development of treatment strategies. We aimed to comprehensively describe the incidence, characteristics, outcomes, and predictive accuracy of the severity indicators among older adults with TBI. Using the Japan Trauma Data Bank, we identified patients aged ≥18 years with TBI from 2004 to 2019. The patients were grouped according to age, and their baseline characteristics, radiological findings, severity, complications, and in-hospital mortality were assessed. Receiver operating characteristic curves were used to assess the accuracy of severity indicators for predicting in-hospital mortality. Of the 94,180 patients who met the inclusion criteria, 50,990 (54.1%) were older adults (aged ≥65 years). Their proportion had increased at 2.1% annually, which exceeded the 0.5% annual increase in the general population. The proportion of women and the prevalence of comorbidities increased significantly with age. Traffic accidents were the leading cause of TBI among young adults, and falling at ground level was the leading cause for those aged ≥75 years. The radiological findings were significantly different among the age groups. The proportion of acute epidural hemorrhage, skull fracture, and diffuse axonal injury decreased and that of acute subdural hemorrhage increased with age. The predictive accuracy of the Glasgow coma scale, revised trauma score, and injury severity score decreased with increasing age. The proportion of older patients with TBI increased more quickly than did the proportion of older people in the general population. The characteristics and predictive accuracy of the severity indicators differed significantly among the different age groups. TBI studies that focus on older patients are necessary.