Although mass shootings are horrid events that grip the public attention, they account for relatively few homicides in the United States. Many more people die in everyday shootings in urban areas that may go unnoticed. The victims of firearm homicide are primarily young, male, or black. Of the 10 945 firearm homicides in 2014, 65.8% of the victims were age 15 to 34 years, 84.3% were men, and 57.5% were black.1
In this issue of JAMA Internal Medicine, we continue our focus on firearm violence2 by publishing 2 studies,3,4 and related commentaries,5,6 on innovative approaches to understanding and responding to firearm homicides in urban areas. In 1 study, Green and colleagues3 analyzed a social network of 138 246 individuals who were arrested in Chicago between 2006 and 2014, focusing on the connections between those arrested together for the same offense.3 The authors show how gunshot violence in Chicago follows an epidemic-like process of social contagion that is transmitted through networks of people by social interactions. The implication is that violence prevention efforts that consider factors related to social contagion in addition to demographic characteristics may prevent more firearm violence than efforts that focus primarily on traditional demographic risk factors, such as age, sex, and neighborhood of residence. A limit of the study is that the authors lacked data on additional relevant factors, such as information about substance abuse, employment, kinship, and gang membership.
In another study, Hohl and colleagues4 examined the association of alcohol and drug use at the individual, family, and neighborhood levels with adolescent homicide in Philadelphia, where almost all adolescent homicides are committed with a firearm. Finding associations between firearm homicide and substance use at all 3 levels, they suggest that violence prevention efforts should simultaneously target multiple levels of substance use, such as individual use, use by caregivers, and density of alcohol outlets and drug availability within specific neighborhoods.
In 2015, there were an estimated 15 696 homicides in the United States; the homicide rate increased by 10.8% as compared to 2014, and guns were used in 71.5% of the cases.7 Nearly 6700 homicides were reported in the 100 largest cities.8 Although public attention has understandably focused on cities, such as Chicago, where the number of homicides has substantially increased in recent years, other cities, such as Los Angeles and New York, have seen their rates decline over time. National homicide rates are still much lower than in the 1990s.7,8 With continued public health and low enforcement efforts, there are abundant opportunities to prevent thousands of firearm-related deaths each year in urban areas. Making and sustaining a difference will not be easy, but the studies by Green et al3 and Hohl et al4 can inform such efforts.
JAMA Editorial. Published Online: January 3, 2017. doi:10.1001/jamainternmed.2016.8509