Predictors of persistent concussion symptoms in adults with acute mild traumatic brain injury presenting to the emergency department.

Objective: To identify risk factors associated with persistent concussion symptoms in adults presenting to the emergency department (ED) with acute mild traumatic brain injury (TBI).

Methods: This was a secondary analysis of a randomized controlled trial conducted in three Canadian EDs whereby the intervention had no impact on recovery or healthcare utilization outcomes. Adult (18-64 years) patients with a mild TBI sustained within the preceding 48 h were eligible for enrollment. The primary outcome was the presence of persistent concussion symptoms at 30 days, defined as the presence of ≥ 3 symptoms on the Rivermead Post-concussion Symptoms Questionnaire.

Results: Of the 241 patients who completed follow-up, median (IQR) age was 33 (25 to 50) years, and 147 (61.0%) were female. At 30 days, 49 (20.3%) had persistent concussion symptoms. Using multivariable logistic regression, headache at ED presentation (OR: 7.7; 95% CI 1.6 to 37.8), being under the influence of drugs or alcohol at the time of injury (OR: 5.9; 95% CI 1.8 to 19.4), the injury occurring via bike or motor vehicle collision (OR: 2.9; 95% CI 1.3 to 6.0), history of anxiety or depression (OR: 2.4; 95% CI 1.2 to 4.9), and numbness or tingling at ED presentation (OR: 2.4; 95% CI 1.1 to 5.2), were found to be independently associated with persistent concussion symptoms at 30 days.

Conclusions: Five variables were found to be significant predictors of persistent concussion symptoms. Although mild TBI is mostly a self-limited condition, patients with these risk factors should be considered high risk for developing persistent concussion symptoms and flagged for early outpatient follow-up.