DOI: 10.1080/16501960410023714

Objective: To evaluate the incidence and causes of mild traumatic brain injury in Sweden. Design: Retrospective, population-based incidence cohort study. Subjects: All persons presenting to hospitals in Sweden between 1987 and 2000 with a discharge diagnosis of ICD-9 code 850 and ICD-10 code S0. 60. Methods: Data source was the Hospital Discharge Register at the National Board of Health and Welfare (Sweden). Incidence rates are stratified by age, gender, mechanism of injury and length of hospital stay. Results: Men had a mean of 209 mild traumatic brain injuries per 100,000 inhabitants and women averaged 148 per 100,000. Men had more mild traumatic brain injury than women at all ages. There were 2 incidence peaks, in the age strata 16-20 years and those over 65 years. Falls were the most common cause of mild traumatic brain injury overall and occurred commonly under the age of 10 years and over the age of 65 years. Motor vehicle and bicycle injuries were the second and third most common causes of mild traumatic brain injury, and had their peak incidence in those aged 16-35 years. Conclusion: Preventative strategies for mild traumatic brain injury should be age and gender specific.