Association of Subacute Mild Traumatic Brain Injury Symptoms With Long-Term Persistent Symptoms, Functional Limitations, and Quality of Life.

Background and objectives: The objective was to evaluate the association of subacute postconcussion symptoms (with the total Rivermead Post-Concussion Questionnaire [RPQ] score) with persistent symptoms, functional limitations, and quality of life at 6 months in patients with mild traumatic brain injury (mTBI).

Methods: This was a secondary analysis of the Transforming Research and Clinical Knowledge of Traumatic Brain Injury, which was a prospective cohort study of patients with TBI and admission Glasgow Coma Scale score between 13 and 15 at 18 US Level 1 trauma centers through 2014-2018. Participants were included in the study if presenting within 24 hours of external force trauma to the head and met the American Congress of Rehabilitation Medicine's criteria for TBI. Participants completed the RPQ, Glasgow Outcome Scale-Extended (GOSE), and Quality of Life after Brain Injury Overall Scale (QOLIBRI-OS). Primary outcomes were persistent symptoms (≥3 individual RPQ symptoms higher than preinjury level), incomplete recovery (GOSE score <8), and lower quality of life (QOLIBRI-OS score ≤51) at 6 months. Multivariable regression models were developed including RPQ clinical cutoffs at 2 weeks and 3 months and risk factors. Adjusted odds ratios (aORs) and 95% CI are reported for multivariable models. Receiver operating characteristic curves were built to identify discriminative ability of the cutoffs with area under the curve (AUC).

Results: The age of the study cohort (n = 2,000) was 41.1 ± 17.3 years; 33% were female (n = 669), 67% male, 57% White (n = 1,141), and 20% Hispanic (n = 408). RPQ total score ≥14 was associated with higher odds of persistent symptoms (aOR 7.25, 95% CI 5.51-9.54), incomplete recovery (aOR 4.85, 95% CI 3.69-6.39), and lower quality of life (aOR 5.31, 95% CI 3.82-7.40) at 6 months compared with patients below the cutoff. AUC for RPQ total score ≥14 at 2 weeks was 0.76-0.81 across outcomes. RPQ total score ≥12 at 3 months was associated with higher odds of persistent symptoms (aOR 18.22, 95% CI 13.09-25.35), incomplete recovery (aOR 8.44, 95% CI 6.18-11.51), and lower quality of life (aOR 7.45, 95% CI 5.40-10.26) at 6 months compared with patients below the cutoff, with AUCs of 0.80-0.88 across outcomes.

Discussion: Clinical cutoffs for a commonly used TBI symptom questionnaire had acceptable-to-excellent discrimination for 6-month outcomes and can be used by clinicians at 2 weeks after injury to identify patients at risk of chronic impairments and refer for targeted rehabilitation.

Classification of evidence: This study provides Class III evidence that overall TBI symptoms at 2 weeks are predictive of 6-month clinical outcomes.