(Reuters Health) - In public mass shootings in the U.S., victims shot with a handgun were more likely to die than in the events associated with a rifle, according to a new study in the Journal of the American College of Surgeons.

“With public mass shootings rapidly on the rise, we wanted to know the reasons why people die and if any aspect is preventable,” said lead study author Dr. Babak Sarani of the George Washington University Center for Trauma and Critical Care in Washington, D.C.

Previous studies show that in mass shootings, about 45 percent of people who are wounded during the event die.

“If we’re going to have conversations around gun violence and public mass shootings, we need to know the facts,” Sarani told Reuters Health by phone. “We started down this road of looking at actual autopsies so there would be no speculation.”

Sarani and colleagues analyzed autopsies from 23 mass shootings from FBI records in 2000-2016 to understand where victims were shot, how many times they were shot, the organs that were hit, the firearm type and if any injuries or deaths were preventable. Of the 232 victims whose bodies were autopsied, 73 were shot with handguns, 105 by rifles, 22 by shotguns and 32 by multiple firearms.

The research team found that events with a handgun were associated with a higher percentage of people killed, whereas events involving a rifle were associated with more people shot. About 26 percent of those shot with a handgun had more than one fatal wound, versus two percent of people shot with a rifle. Handguns were also more likely to be associated with brain and heart injuries.

“All of us were shocked. We came to the table with our bias that an assault weapon would be worse,” Sarani said. “This should inform the medical community about what to expect at trauma centers and lawmakers about reasonable gun laws.”

The differences in firearm lethality could be due to several factors, Sarani explained. Close-range handguns and longer-range rifles change the distance between the shooter and victim, as well as the accuracy and velocity of the bullet. Although the higher muzzle velocity of a rifle is typically associated with more accuracy, public mass shootings with handguns tend to lead to more gunshot wounds per victim and a higher likelihood of injuries to vital organs.

“We’ve been careful in these studies to not come across as anti-Second Amendment but to better understand what reasonable legislation could be aimed at gun-related violence,” Sarani said. “How do you know what’s reasonable when you don’t know what the problem is?”

A limitation of the study is that autopsy reports can’t explain what happened on the scene of the mass shooting or how or when a patient died in route to the hospital, said Dr. Alan Cook, a surgeon and director of trauma research at Dignity Health in Chandler, Arizona. Cook, who wasn’t involved with this study, has previously researched gunshot wounds that result in hospitalization in the U.S.

“Firearm violence has become background noise in this country,” Cook told Reuters Health by phone. “We see these tragedies all the time on the news, and we need a motion that will decrease this feature of American culture.”

SOURCE: bit.ly/2EXYI4G Journal of the American College of Surgeons, online December 7, 2018.