Clinical Epidemiology of Adults With Moderate Traumatic Brain Injury

Objectives: To characterize admission patterns, treatments, and outcomes among patients with moderate traumatic brain injury. Design: Retrospective cohort study. Setting: National Trauma Data Bank. Patients: Adults (age > 18 yr) with moderate traumatic brain injury (International Classification of Diseases, Ninth revision codes and admission Glasgow Coma Scale score of 9-13) in the National Trauma Data Bank between 2007 and 2014. Interventions: None. Measurement and Main Results: Demographics, mechanism of injury, hospital course, and facility characteristics were examined. Admission characteristics associated with discharge outcomes were analyzed using multivariable Poisson regression models. Of 114,066 patients, most were white (62%), male (69%), and had median admission Glasgow Coma Scale score of 12 (interquartile range, 10-13). Seventy-seven percent had isolated traumatic brain injury. Concussion, which accounted for 25% of moderate traumatic brain injury, was the most frequent traumatic brain injury diagnosis. Fourteen percent received mechanical ventilation, and 66% were admitted to ICU. Over 50% received care at a community hospital. Seven percent died, and 32% had a poor outcome, including those with Glasgow Coma Scale score of 13. Compared with patients 18-44 years, patients 45-64 years were twice as likely (adjusted relative risk, 1.97; 95% CI, 1.92-2.02) and patients over 80 years were five times as likely (adjusted relative risk, 4.66; 95% CI, 4.55-4.76) to have a poor outcome. Patients with a poor discharge outcome were more likely to have had hypotension at admission (adjusted relative risk, 1.10; 95% CI, 1.06-1.14), lower admission Glasgow Coma Scale (adjusted relative risk, 1.37; 95% CI, 1.34-1.40), higher Injury Severity Score (adjusted relative risk, 2.97; 95% CI, 2.86-3.09), and polytrauma (adjusted relative risk, 1.05; 95% CI, 1.02-1.07), compared with those without poor discharge outcomes. Conclusions: Many patients with moderate traumatic brain injury deteriorate, require neurocritical care, and experience poor outcomes. Optimization of care and outcomes for this vulnerable group of patients are urgently needed.