In the last decade, Philadelphia hospitals have seen droves of patients suffering from gunshot wounds. It’s common for emergency rooms to receive “clustered arrivals” — multiple bullet-ridden people all rushed through the doors at the same time.

Trauma centers in the city, sadly, have grown accustomed to the phenomenon. “It’s a situation we have to be prepared for — and have a plan for,” said Jessica Beard, a trauma surgeon at Temple Hospital.

Now public health professionals are wondering: Should we count these clusters as mass shootings?

New research shows that from 2005 to 2015, Philadelphia hospitals recorded 54 clustered arrivals of firearm patients. In each instance, four or more patients arrived at the hospital within 15 minutes. They didn’t necessarily have the same shooter, but they happened at roughly the same time, in the same geographic region of the city.

Those four-and-a-half dozen cluster instances over the course of a decade measures out to at least one every three months, according to the Journal of the American College of Surgeons report.

“We’re trying to describe this phenomenon that we see as trauma surgeons,” said Beard, a researcher on the study. “What we see at Temple and around the city of Philadelphia, we think of as ‘everyday mass shootings.'”

Despite the frequency of mass shootings in the United States, there no specific definition for them just yet. Most media outlets and criminologists follow the FBI’s parameters for a mass murderer, which is defined as someone who kills four or more people in a single incident.

So from a hospital’s point of view, when they have to treat four-plus people with firearm wounds at the exact same time, Philly’s 54 clusters probably qualify.

It’s a classification that trauma surgeons are advocating for, with the hope that it’ll shed more light on urban gun violence.

The most well-known mass shootings are at schools, nightclubs, newsrooms and concerts — and though tragic, they’re not quite representative of America’s gun violence epidemic.

Occurring more often than those cases are the daily instances of gun violence faced by cities, especially Philadelphia, which had a higher shooting rate in 2018 than New York, Chicago, Los Angeles and Washington, D.C.

Beard theorizes that if we understand the capacity of urban gun violence as a near-monthly mass shooting, perhaps it will generate more attention — and ideally some action, too.

“Traditionally, the mass shootings that receive media attention, they’re very high profile,” Beard said. “But that may not help prevent victims of gun violence in urban centers.”