What is the annual incidence of TBI?

• A. 506.4 per 100,000
• B. 1.75 million occur annually
• C. 4 million
• D. 80 billion

Answer: (B)

Incidence is the number of new traumatic brain injury cases that occur in a given time period, typically one year. In the United States, the best-supported figure is about 1.7 to 1.75 million new TBIs each year, reflecting all severities from mild concussions to more serious injuries. This estimate captures cases seen in emergency departments, hospitals, and even some that go unreported. The other numbers mix units or scales: a rate given per 100,000 people isn’t a raw annual count by itself, and converting it depends on population size; the value listed per 100,000 would translate to roughly 1.5 million in a large country but isn’t the standard annual incidence used in exams. A figure like 4 million is higher than typical U.S. estimates, and 80 billion is not plausible as an incidence count. So the closest, widely cited annual incidence is about 1.75 million new TBIs per year.