Mild traumatic brain injuries presenting to Swedish hospitals in 1987-2000.

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.