Objective To estimate the prevalence of post-concussive symptoms (PCS) following head injury among adolescents in full-time education and to identify prognostic factors at presentation to the emergency department (ED) that may predict the development of PCS.

Methods An observational cohort study of all head injured patients aged 13–21 and in full-time education presenting to an inner city ED was performed. Subjects were followed up at 1 and 6 months after injury by structured telephone interview to assess for the presence of symptoms or ongoing disability. Presentation data of those identified as having PCS underwent regression analysis to isolate potential prognostic indicators for such problems.

Results Of the 188 patients recruited, 5.9% (95% CI 3.3% to 10.2%) still had some symptoms after 6 months, with half of these claiming that such symptoms were affecting everyday living. Of these patients, 82% were assaulted as the cause of their injury and nearly 40% had no conventional indicators of head injury severity at presentation. After 1 month, 46/188 (24.5%, 95% CI 18.9% to 31.1%) patients had some degree of symptoms, most of whom were discharged directly from the ED. Potential prognostic indicators identified were a reduced Glasgow Coma Score (GCS) (<15) at presentation and being assaulted as the cause of injury.

Conclusion The prevalence of PCS 6 months following head injury for the selected sub-group was 5.9%, and 10.6% if assaulted. Most patients who developed PCS were discharged directly from the ED.