Facts, Demographics and Risk Factors

Facts About Traumatic Brain Injury

  • From 1995 to 2001, the CDC estimated that at least 1.4 million TBIs occurred in the United States (9).
  • Of these 1.4 million TBIs, 50,000 resulted in death, 235,000 resulted in hospitalization and 1.1 million were treated and released from the emergency department (9).
  • It is unknown how many people will experience a TBI and not be seen in a hospital or ED or who will receive no care at all (9).
  • The risk of TBI is higher for males than females, with adolescents, young adults and the elderly at the highest risk of TBI injuries (6,9-11).
  • The most common causes of TBI deaths are attributed to motor vehicle crashes, falls and violence (23).
  • In the US, African Americans have higher rates brain injury than other groups (9,11).
  • Lower socioeconomic status is also associated with increased risk of brain injury (12).

Demographics and Risk Factors

Males are significantly more likely to sustain a TBI that results in death or medical treatment compared to females (8). Overall, approximately 1.5 times as many TBIs occur among males as females. In almost every age group, TBI rates are higher for males that for females (9).

The elderly (i.e. those aged 75 and older) and young adults (i.e. 15-24) sustain the highest rates of TBI-related deaths and hospitalizations whereas infants and young children (i.e., 0 – 14 years of age) are the most likely to visit the emergency department or a physician’s office for a minor TBI (6,9,11). For children aged 0 to 14 years, TBI results in an estimated 2,685 deaths, 37,000 hospitalizations and 435,000 ED visits annually (9).

Ethnic and socio-economic origin are significant risk factors in the occurrence of TBI. The African-American population has a higher death rate from TBI than other ethnic groups in the United States (9,11). Most of these incidents are related to homicide. TBI hospitalization rates are highest among African Americans and American Indians/Alaska Natives (9). Lower socioeconomic status is also associated with increased risk of TBI (12).

Another significant risk factor in the incidence of brain injury is the occurrence of a previous brain injury. These repeated insults to the brain are most office related to multiple concussions. In the sports literature, there is strong evidence that suggests a prior history of a TBI is associated with an increased risk of another TBI among athletes (13-15) After a TBI incident, the potential risk for subsequent multiple injuries is extremely common. Among people with an initial TBI incident, the risk of a second injury is three times that of the general population, and after a second brain injury, the potential risk for a third one increases to eight times that of the normal average (16). While there have been studies of persons with a repeat TBI which document the proportion of a TBI group with a prior history of TBI, no studies have systematically evaluated the risk of recurrent TBI among persons who sustain a TBI severe enough to require a hospitalization or ED visit (17,18).