A nationwide study examining the safety of TASERs used by law enforcement agencies suggests the devices are safe, causing a low occurrence of serious injuries.

"This study is the first large, independent study of injuries associated with TASERs. It is the first injury epidemiology study to review every TASER deployment and to reliably assess the overall risk and severity of injuries in real world conditions," said William Bozeman, M.D., the lead investigator and an emergency medicine specialist at Wake Forest University School of Medicine. "The injury rate is low and most injuries appear to be minor. These results support the safety of the devices."

Bozeman presented the study results at the American College of Emergency Physicians' Research Forum in Seattle, Wash., Oct. 8. In a review of nearly 1,000 cases, 99.7 percent of those subjected to a TASER had mild injuries, such as scrapes and bruises, or none at all. Only three subjects (0.3%) suffered injuries severe enough to need hospital admission. Two had head injuries suffered in falls after TASER use. A third subject was admitted to a hospital two days after arrest with a medical condition of unclear relationship to the TASER. Two subjects died, but autopsy reports indicate that neither death was related to the TASER. Earlier partial results involving 597 cases were published in the September issue of Annals of Emergency Medicine.

The independent prospective study was funded by the National Institute of Justice and included six law enforcement agencies across the United States. A tactical physician at each participating agency reviewed police and medical records after each successful application of a TASER. Injuries were identified and classified as mild, moderate, or severe and their relationship to the TASER was classified as direct, indirect, or uncertain.

TASERs are used by many police departments in the United States and are credited with decreasing police officer and suspect injuries and deaths due to police use of force. However, the devices have been surrounded with controversy.

"This is the largest independent study to date, and the first to detail the medical effects of TASERs under real-world conditions," said Bozeman. "With physician review of 100 percent of TASER uses, this study promises to give us the best information yet on the medical risks of these weapons."

Bozeman said results from previous studies were limited by the use of animal models and of healthy police volunteers in training settings, not criminal suspects in real-world conditions.

"The TASER is a weapon and it can clearly cause injuries and even deaths in some cases," Bozeman said. "The question is 'how likely is it to cause a significant injury' and whether that risk of injury outweighs the benefits it brings."