“It's Not Only the Injury but Also the Kind of Head.” Factors Influencing Outcome After Traumatic Brain Injury

Abstract

ObjectiveGiven the high variability in traumatic brain injury (TBI) outcomes and relative lack of examination of the influence of noninjury factors on outcome, this study aimed to examine factors associated with functional outcome at 1 and 2 years after moderate to severe TBI, including both preinjury and injury-related factors. DesignObservational cohort study. SettingInpatient hospital recruitment with outpatient follow-up at 1 and 2 years post injury. ParticipantsIndividuals with moderate to severe TBI were recruited prospectively into a Longitudinal Head Injury Outcome Study. Of the eligible 3253 individuals who were eligible, 1899 participants consented to the study (N=1899). Main Outcome MeasureFunctional outcome was measured using the Glasgow Outcome Scale–Extended (GOS-E). Results1476 participants (73.6% males) and 1365 participants (73% males) completed the GOS-E at 1 and 2 years post injury. They had a mean age at injury of 40 years and mean duration of post-traumatic amnesia (PTA) of 26 days. Good recovery, representing return to previous activities on the GOS-E (score 7-8), was present in 31% of participants at 1 year post injury and 33.5% at 2 years post injury. When predictor variables were entered into regression together, good outcome was significantly associated with not being from a culturally and linguistically diverse background and not having preinjury mental health or alcohol treatment, shorter PTA duration, and absence of limb injuries at both 1 and 2 years; higher education was also a significant predictor at 1 year post injury. ConclusionsAlongside consideration of injury severity, consideration of preinjury factors is important to inform prognostication and rehabilitation planning.