Abstract
Objective: To determine the comparative predictive validity of the Subgroups for Targeted Treatment modified for concussion (STarT-C) with full-length psychological measures (legacy questionnaires) in adults, six months after mild traumatic brain injury (mTBI).
Materials and methods: Participants (n = 107) were recruited from outpatient concussion services in New Zealand and assessed on average 6 weeks (Time 1) and 6 months after mTBI (Time 2). The primary outcome was post-concussion symptoms at Time 2 measured with the Rivermead Post-concussion Symptoms Questionnaire (RPQ). Comparative predictive validity was determined by comparing the STarT-C at Time 1 with full-length legacy questionnaires that measured STarT-C constructs (distress, depression, fear avoidance, recovery expectations, catastrophizing) at Time 1.
Results: The STarT-C total score and psychosocial sub-score showed significant correlations with all psychological legacy questionnaires at Time 1 (r = ~0.3 to ~ 0.7). The STarT-C showed similar additional predictive value on symptoms at Time 2, as all legacy psychological questionnaires together (delta R2 = 8% vs. delta R2 = 8%).
Conclusions: The STarT-C showed comparable prognostic value for post-concussion symptom outcomes with a battery of psychological questionnaires. Further research should consider if stratified risk using STarT-C high, medium, and low sub-categories improves targeted treatment referral decision making by clinicians and mTBI outcomes.