The incidence of TBI refers to the number of new cases identified in a specific time period. The prevalence refers to the number of individuals who are living with TBI in a given time period. Every year, at least 1.7 million TBIs occur in the United States (across all age groups), and they are a contributing factor in about a third (30.5%) of all injury-related deaths (Faul, Xu, Waldo, & Coronado, 2010). Older adolescents (ages 15 to 19 years), older adults (ages 65 years and older), and males across all age groups are most likely to sustain a TBI (Faul et al., 2010).
The incidence of TBI, as measured by combined emergency department (ED) visits, hospitalizations, and deaths, has steadily risen from 2001 to 2010. For example, from 2001 to 2005, the TBI rates increased from 521 to 616 per 100,000 population and, in 2010, increased to 824 per 100,000 population (Centers for Disease Control and Prevention [CDC], 2014). However, upon closer examination of TBI rates, it appears that TBI-related ED visits increased by 70% from 2001 to 2010, while hospitalization rates increased by only 11%. Additionally, deaths related to TBI decreased by 7% over the same 10-year span (CDC, 2014). It is believed that factors, such as automobile safety, seat belt use, helmet use, and better overall treatment for severe TBI in prehospital and hospital settings, while unable to prevent TBIs entirely, have mitigated their severity and thus mortality.
Between 3.2 and 5.3 million persons (1.1%-1.7% of the U.S. population) live with long-term disabilities that result from TBI. These are likely underestimates of the prevalence of TBI, because they do not include persons with TBI sequelae who were treated and released from EDs, those who sought care in other health-care settings, and those who did not seek treatment (Alverson et al., 1999; Selassie et al., 2008; Zaloshnja, Miller, Langlois, & Selassie, 2008).