An accident is an unplanned event that sometimes has inconvenient or undesirable consequences, other times being inconsequential. The occurrence of such an event may or may not have unrecognized or unaddressed risks contributing to its cause. Most scientists who study unintentional injury avoid using the term "accident" and focus on factors that increase risk of severe injury and that reduce injury incidence and severity.
Poisons, vehicle collisions and falls are the most common causes of fatal injuries. According to a 2005 survey of injuries sustained at home, which used data from the National Vital Statistics System of the United States National Center for Health Statistics, falls, poisoning, and fire/burn injuries are the most common causes of death.
The United States also collects statistically valid injury data (sampled from 100 hospitals) through the National Electronic Injury Surveillance System administered by the Consumer Product Safety Commission. This program was revised in 2000 to include all injuries rather than just injuries involving products. Data on emergency department visits is also collected through the National Health Interview Survey. In The U.S. the Bureau of Labor Statistics has available on their website extensive statistics on workplace accidents.