Mild traumatic brain injury in New Zealand: factors influencing post-concussion symptom recovery time in a specialised concussion service.

INTRODUCTION By 2020, traumatic brain injuries (TBIs) are predicted to become the third largest cause of disease burden globally; 90% of these being mild traumatic brain injury (mTBI). Some patients will develop post-concussion syndrome. AIM To determine whether the time between sustaining a mTBI and the initial assessment by a specialised concussion service, along with the post-concussion symptoms reported at the assessment, affected recovery time. METHODS A retrospective medical record review of clients who had completed the Rivermead Post-Concussion Questionnaire (RPQ) at their initial assessment and were discharged from a large metropolitan concussion service in New Zealand was undertaken over a 6-month period in 2014 (n = 107). Using correlations, General Linear Mixed-effects Models (GLMM) and linear regressions, we explored associations between factors including ethnicity, gender and accident type, along with individual RPQ symptom scores and cluster scores, with time from injury to initial assessment by the specialised concussion service and initial assessment to discharge. RESULTS Time from injury to initial assessment by a specialist concussion service was correlated with proportionally more psychological symptoms present at initial assessments (r = 0.222, P = 0.024); in particular, feeling depressed or tearful (r = 0.292, P = 0.003). Time to discharge was correlated with individual RPQ symptom proportions present at initial assessment for headaches (r = -0.238, P = 0.015), sensitivity to noise (r = 0.220, P = 0.026), feeling depressed or tearful (r = 0.193, P = 0.051) and feeling frustrated or impatient (r = 0.252, P = 0.003), along with the psychological cluster proportion (r = 0.235, P = 0.017) and the total RPQ score (r = 0.425, P < 0.001). CONCLUSION Prompt diagnosis and treatment of mTBI may minimise the severity of post-concussion symptoms, especially symptoms associated with mental health and wellbeing.