Neuroepidemiology of traumatic brain injury.

Traumatic brain injury (TBI) is a significant public-health concern. TBI is defined as an acute brain injury resulting from mechanical energy to the head from external physical forces. Some of the leading causes of TBI include falls, assaults, motor vehicle or traffic accidents, and sport-related concussion. Two of the most common identified risk factors are sex (males are nearly three times more likely to suffer a TBI than females); and a bimodal age pattern (persons 65 years and older, and children under 14 years old). It is estimated that approximately 1.5-2 million Americans suffer from TBI annually. TBIs account for around 1.4 million emergency room visits, 275 000 hospital admissions, and 52 000 deaths in the USA each year. TBI contributes to approximately 30% of all deaths in the USA annually. In Australia, it is estimated that approximately 338 700 individuals (1.9% of the population) suffer from a disability related to TBI. Of these, 160 200 were severely or profoundly affected by acquired brain injury, requiring daily support. In the UK, TBI accounted for 3.4% of all emergency department attendances annually. An overall rate of 453 per 100 000 was found for all TBI severities, of which 40 per 100 000 (10.9%) were moderate to severe. TBI often results in residual symptoms that affect an individual's cognition, movement, sensation, and/or emotional functioning. Recovery and rehabilitation from TBI may require considerable resources and may take years. Some individuals never fully recover, and some require lifetime ongoing care and support. TBI has an enormous social and financial cost, with estimates of the annual financial burden associated with TBI ranging between 9 and 10 billion US dollars.