OBJECTIVE: To investigate sex differences in symptoms, structure of symptoms, disability and life satisfaction 3 years after mild traumatic brain injury. Secondary aims were to find risk factors for adverse outcome. DESIGN: Population-based cohort study.Patients: The cohort comprised 137,000 inhabitants at risk in a defined population served by a single hospital in northern Sweden. Patients attending the emergency department following a mild traumatic brain injury in 2001 were included. METHODS: Of 214 patients aged 18–64 years, 163 answered a questionnaire on symptoms, disability, and life-satisfaction 3 years post-injury. The instruments were analysed with descriptive statistics. A principal component analysis of the Rivermead Post-Concus...