There are 67 million bicyclists in the US, accounting for approximately 15 billion hours of riding per year. Unfortunately, injuries and fatalities do occur among bicyclists. In the United States, the toll of bicycle injuries is approximately 900 deaths, 23,000 hospital admissions, 580,000 emergency department visits, and approximately 1.2 million physician office visits each year.
In a study of Seattle area hospital emergency departments, 43.3% of the injuries from bicycling occurred in children under 13 years of age. Motor vehicle involvement was an important predictor of severe and fatal injury, as those hit by motor vehicles were 14.1 times more likely to be killed.
Helmet use was associated with a 93% decrease in risk of fatality, which, alternatively stated, means that non-helmeted riders were 14.3 times more likely to be involved in a fatal bicycle crash.
Source: Injury Prevention, 2015