Effect of Fever on the Clinical Outcomes of Traumatic Brain Injury by Age.

Background and objective: Fever is a common symptom in patients with traumatic brain injury (TBI). However, the effect of fever on the clinical outcomes of patients with TBI is not well characterized. Our study aims to determine the impact of fever on the clinical outcomes of patients with TBI and test the interaction effect of fever on study outcomes according to age group. Materials and methods: Our retrospective study included adult patients with TBI who were transported to a level 1 trauma center by the emergency medical services (EMS) team. The main exposure is fever, defined as a body temperature of 38 °C or above, in the emergency department (ED). The primary outcome was mortality at hospital discharge. We conducted a multivariable logistic regression analysis to estimate the effect sizes of fever on study outcomes. We also conducted an interaction analysis between fever and age group on study outcomes. Results: In multivariable logistic regression analysis, patients with TBI who had fever showed no significant difference in mortality at hospital discharge (aOR, 95% CIs: 1.24 (0.57−3.02)). Fever significantly increased the mortality of elderly patients (>65 years) with TBI (1.39 (1.13−1.50)), whereas there was no significant effect on mortality in younger patients (18−64 years) (0.85 (0.51−1.54)). Conclusions: Fever was associated with mortality only in elderly patients with TBI.