(Reuters Health) - As mass-casualty events and violent attacks in the U.S. continue to increase, military and emergency medicine experts are recommending that public venues install bleeding-control kits for at least 20 victims.

These kits, equipped with nitrile gloves, a basic tourniquet, wound dressing to stop severe bleeding, rolled gauze and trauma scissors, could allow bystanders to help save lives after bombings, mass shootings and stabbings, the study authors write in the American Journal of Public Health.

“We’ve seen a real revolution in battlefield medicine during the past 15 years in Iraq and Afghanistan, and the military has learned how to care for trauma patients and improve survival,” said study leader Dr. Craig Goolsby of the Uniformed Services University of the Health Sciences in Bethesda, Maryland.

Soldiers who have learned hemorrhage-control skills have reduced battlefield deaths from 16 percent to 10 percent by being able to respond before medics arrive, the authors write. In recent mass-casualty events such as the bombings at the Boston Marathon, the public also became “immediate responders.”

A national campaign, called “Stop the Bleed,” encourages the public to learn how to stop life-threatening bleeding and advocates for access to bleeding-control kits in public areas and office buildings.

“The Stop the Bleed campaign takes the lessons from the battlefield and brings them to the American public, prioritizing point-of-injury bleeding,” Goolsby said in a phone interview. “But the question we often hear is how many kits to install.”

Since no formal guidelines exist about the quantities of supplies that should be stocked in public places, Goolsby and colleagues analyzed data on mass-casualty events to determine the average number of deaths and injuries in such circumstances.

From data on gun casualties in U.S. mass shootings, they found that the average active-shooter event involved five to 11 victims. Fatality rates ranged from 21 to 51 percent, which public bleeding-control kits could help to reduce, the authors write.

Using U.S. and international data, they looked at three other categories of attacks: intentional vehicle attacks, knife attacks and bombings.

Focusing on 16 intentional vehicle attacks in North America, Europe and Israel, they found an average of eight deaths and 43 injuries per attack. And in a review of 161 terrorism-related stabbings and machete attacks, the average number of victims was roughly two per attack.

The current study also found that suicide bombings killed 10 people and injured 24, on average.

Based on these analyses, the researchers recommend bleeding-control supplies to treat at least 20 people in any event that could occur, including everyday accidents.

“It’s a limited analysis based on limited data, but it’s a reasonable starting place,” Goolsby said.

Bleeding-control kits typically cost $50-$75 and include instructions so bystanders can quickly grab items in the midst of chaos to take care of a victim. Researchers and policymakers are now determining the best place to put these kits in public venues, including next to automated external defibrillators.

“The public has learned that those boxes are meant for use during heart attacks, so we should co-locate other supplies for medical emergencies,” said Dr. Lenworth Jacobs of the University of Connecticut in Hartford, who directs the Stop the Bleed program but wasn’t involved in the current study.

Those interested in learning how to stop bleeding during mass casualty events or everyday accidents can learn more at BleedingControl.org.

“Accidents with kitchen knives or chainsaws are more common than terrorist activities, and these kits help then, too,” Jacobs told Reuters Health in a phone interview. “Bleeding control is a life skill that everyone should have.”

SOURCE: bit.ly/2Fnxp3S American Journal of Public Health, online December 20, 2018.