Age and sex-mediated differences in six-month outcomes after mild traumatic brain injury in young adults: a TRACK-TBI study

Abstract

Introduction: Risk factors for young adults with mTBI are not well understood. Improved understanding of age and sex as risk factors for impaired six-month outcomes in young adults is needed. Methods: Young adult mTBI subjects aged 18-39 years (18-29y; 30-39y) with six-month outcomes were extracted from the Transforming Research and Clinical Knowledge in Traumatic Brain Injury Pilot (TRACK-TBI Pilot) study. Multivariable regressions were performed for outcomes with age, sex, and the interaction factor age-group*sex as variables of interest, controlling for demographic and injury variables. Mean-differences (B) and 95% CIs are reported. Results: One hundred mTBI subjects (18-29y, 70%; 30-39y, 30%; male, 71%; female, 29%) met inclusion criteria. On multivariable analysis, age-group*sex was associated with six-month post-traumatic stress disorder (PTSD; PTSD Checklist-Civilian version); compared with female 30-39y, female 18-29y (B= -19.55 [-26.54, -4.45]), male 18-29y (B= -19.70 [-30.07, -9.33]), and male 30-39y (B= -15.49 [-26.54, -4.45]) were associated with decreased PTSD symptomatology. Female sex was associated with decreased six-month functional outcome (Glasgow Outcome Scale-Extended (GOSE): B= -0.6 [1.0, -0.1]). Comparatively, 30-39y scored higher on six-month nonverbal processing speed (Wechsler Adult Intelligence Scale-Processing Speed Index (WAIS-PSI); B= 11.88, 95% CI [1.66, 22.09]). Conclusions: Following mTBI, young adults aged 18-29y and 30-39y may have different risks for impairment. Sex may interact with age for PTSD symptomatology, with females 30-39y at highest risk. These results may be attributable to cortical maturation, biological response, social modifiers, and/or differential self-report. Confirmation in larger samples is needed; however, prevention and rehabilitation/counseling strategies after mTBI should likely be tailored for age and sex.

Keywords: Age factors; common data elements; functional disability; mild traumatic brain injury (mTBI); post-traumatic stress disorder (PTSD); risk factors; sex; young adults.

Figure 1.. Flowchart of included subjects

Flowchart of 100 mild traumatic brain injury subjects aged 18–39 years meeting inclusion criteria from the TRACK-TBI Pilot study.

Figure 2.. Six-month outcomes by age-group and sex

Six-month adjusted scores on outcome measures displayed by age group on the x-axis (18–29y, 30–39y) and sex (male: mean displayed as circle; female: mean displayed as square). Colored lines indicated clinical cutoffs for screening and/or classification. All scores are adjusted for race, education, psychiatric history, mechanism of injury, loss of consciousness, Glasgow Coma Scale, intracranial lesion on computed tomography, and polytrauma. Bars represent standard errors. Panel A: Posttraumatic stress disorder (PTSD) symptomatology measured by the PTSD Checklist-Civilian Version (PCLC); higher scores indicate worse severity, and the red line at PCLC=32 indicates the clinical cutoff for PTSD screening in the civilian population. Panel B: Postconcussional symptomatology (PCS) measured by the Rivermead Postconcussional Symptoms Questionnaire-13 item score (RPQ13); higher scores indicate worse severity, and the red line at RPQ13=20 indicates the clinical cutoff for PCS screening. Panel C: Functional recovery measured by the Glasgow Outcome Scale-Extended (GOSE); higher scores indicate better functional recovery, and a score of 8 indicates full recovery to baseline function. The blue line at GOSE 7 indicates the lower limit of “good recovery”, while the red line at GOSE 6 indicates the upper limit of “moderate disability”. Panel D: Global psychiatric burden measured by the Brief Symptom Inventory-18 Global Severity Index (BSI18 GSI), an overall measure of somatization, depression, and anxiety symptoms; higher scores indicate worse severity, and the red line at BSI18 GSI=63 indicates the clinical cutoff for screening for psychiatric symptoms.