You might be able to catch gun violence like a disease, study says

Several studies have examined how gun violence can spread in neighborhoods and communities, but according to a new study, a new model might have particular success for those trying to prevent such violence — one researchers already use to examine the spread of disease.

In a study published Monday in JAMA Internal Medicine, researchers at Harvard and Yale used models currently applied to epidemics to study how gun violence might spread from person to person, instead of generally putting people in one community at higher risk. The study found that a “social contagion” model, when paired with demographic data like sex and age, could help predict the risk that someone might be shot in about 63 percent of cases studied.

“Gunshot violence follows an epidemic-like process of social contagion that is transmitted through networks of people by social interactions,” the study authors wrote. Adding models like those that predict the spread of disease to existing models could “have the potential to prevent more shootings,” they added.

According to the CDC, nearly 11,000 people in the United States were killed by a firearm in 2014.

The study examined gun violence and arrest data in Chicago from 2006 to 2014 and specifically looked at more than 138,000 individuals that were linked by a network that the researchers based off arrest patterns. It found that people who were exposed to gun violence by others that they knew had a higher risk of being shot, sometimes more than once.

Like epidemics, the gun violence “contagion” that was modeled in the study also took time to spread. Those who were exposed to gun violence through another person were, on average, shot about 125 days after the “infector,” according to the study.

But some questions remain unanswered — including why some people’s cases fit the epidemic model and others’ didn’t. The study also based people’s connections to each other based only on their arrest patterns, the authors acknowledged, meaning additional social factors like friendships or shared workplaces were not taken into consideration.

“Future research should expand its focus on the types of networks that foster and abate the contagion of violence,” they wrote. “Developing our understanding of resilience in networks might advance a preventive approach to mitigating the effects of gun violence that looks not simply to respond to shootings that have already happened but also to bolster networks that might inoculate from the potential for future shootings.”

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