Factors associated with variability in recovery after mild traumatic brain injury among adults referred to outpatient concussion clinics

BACKGROUND: To understand factors associated with symptom and disability recovery trajectories among adults referred to outpatient clinics after mild traumatic brain injury. METHODS: Adults (n = 110; mean age 39 years, 36% men), were assessed at clinic intake (baseline mean 6.5 weeks), and monthly thereafter for 6 months. Validated questionnaires assessed distress, fear avoidance and catastrophising at baseline, and mild traumatic brain injury symptoms and disability. Using correlations and linear mixed modelling, we explored associations between demographic characteristics (age, gender), baseline psychological factors and recovery as a function of time. RESULTS: The models predicted improvement in symptoms (R2 = 0.22) and disability (R2 = 0.37). After adjusting for baseline severity of symptoms and disability, higher distress was associated with slower recovery and greater variability for symptoms (P = 0.06) and disability (P < 0.01). Higher baseline catastrophising predicted less symptom improvement (P = 0.02). Those with higher fear avoidance behaviour at baseline showed greater variability in disability outcomes (P = 0.02), even when other psychological variables were accounted for. CONCLUSIONS: Participants showed improvements on average, in both symptoms and disability. Variability and rates of recovery were associated with distress, catastrophising and fear avoidance. Clinicians can target such psychological factors in treatment and anticipate recovery fluctuations, normalising these while maintaining cautiously optimistic messaging regarding expected good prognosis after mild traumatic brain injury.