Predicting recovery outcomes following mild traumatic brain injury in an Australian community cohort: results from the Concussion Recovery Study (CREST)

Abstract Background Most people recover well following mild traumatic brain injury (mTBI), however some experience persisting post-concussion symptoms (PPCS) for months or years. Our aims were (i) to evaluate the presence and impact of PPCS on return to functional activities over a 12-month period; and (ii) identify pre-, peri- and post-injury factors predictive of PPCS in an Australian community-based cohort at 3- and 12-months. Methods Adults (18–65 years) with mTBI were assessed by telephone within 7 days post-injury to capture demographics, pre-injury health status, injury circumstances (including mechanism, site of head impact) and symptoms. The primary outcome measure was the presence of PPCS, measured with the Post-Concussion Symptom Scale (PCSS). Logistic regression identified predictors of PPCS at 3- and 12-months. Results Of 232 participants, 49.7% had PPCS at 3-months and 45.6% at 12-months. Return to work was 96.7% at 3-months and 96.9% at 12-months, despite nearly 50% reporting PPCS. Participants with a high initial symptom burden (PCSS ≥30) were six-times more likely to experience PPCS at 3-months (adjusted odds ratio [aOR] 6.17, 95%CI 2.63–14.46) and three-times as likely to have PPCS at 12-months (aOR 2.70, 95%CI 1.01–7.23). Acute symptoms of “feeling slow” or “nervousness” predicted PPCS at 3-months (aOR 2.97 and 2.74, respectively), but not at 12-months. Conclusion Of those who completed follow-up, nearly half had persistent symptoms at 12-months, often continuing to work despite symptoms. High initial symptom severity and acute symptoms may help clinicians identify those needing early targeted follow-up to reduce the burden of PPCS.