Long-Term Outcomes of Patients Seeking Specialized Health Care For Persisting Post-Concussion Symptoms After a Mild Head Injury

OBJECTIVE: To examine long-term outcomes of persisting post-concussion symptoms (PPCS) after mild head injury for patients seeking specialist care. DESIGN: Longitudinal cohort study. Baseline interview at outpatient admission, follow-up interviews at 3, 6, 12, 18, 24, 30, 36, 48 and 60 months post-injury, and 5 years after outpatient admission. SETTING: Rehabilitation clinic. PARTICIPANTS: Patients (n=191) with PPCS following mild head injury the past five years. INTERVENTIONS: N/A. MAIN OUTCOME MEASURES: Symptoms assessed by Rivermead Post-Concussion Symptoms Questionnaire, functioning via Glasgow Outcome Scale-Extended and return to full-time work. Linear and logistic mixed models with and without interaction terms evaluated outcomes over time, while within-subject change was assessed from participants' first to final assessments. RESULTS: The sample comprised 800 assessments (mean 4.2 (SD 1.7) per participant). Patients were divided into groups by time from injury to outpatient admission (group 1: 0-3 months (n=44); group 2: 3-6 months (n=54); group 3: 6-12 months (n=47); group 4: 12-24 months (n=26); group 5: 24-60 months (n= 20). Although the groups had similar clinical characteristics at outpatient admission, their outcomes over time differed. Substantial symptom reduction and functional improvement were observed over time in groups 1-4, but not in group 5. Most symptom relief across groups occurred in the months following outpatient admission. CONCLUSIONS: In patients seeking care for PPCS, most exhibited improvement over time and worsening was rare. However, many still experienced symptoms years after outpatient admission, and outpatient admission two years or more post-injury was associated with significantly poorer outcomes.