“How Many People are Shot in the U.S.?” Brady’s Embrace of Better Data

The CDC’s gun injury data is shockingly unreliable. Brady is moving away from it — and we hope others in the gun violence prevention movement will follow.

By Dr. Kyleanne Hunter, Brady’s Vice President of Programs

How many Americans are injured by gun violence every year? Every day? These are important questions to answer, not only for organizations like Brady, but also for the American public as well. The importance of having reliable data in order to accurately understand the scope of any major problem — especially an epidemic as sweeping as gun violence — is undeniable. It is impossible to effectively solve a problem that isn’t accurately understood.

But recently, it’s become clear that there are problems with some of the data used to understand the scale and scope of gun violence in the United States.

Historically, the gun violence prevention movement has relied on gun injury estimates by the Centers for Disease Control and Prevention’s (CDC) to determine the number of people shot and injured in the United States. But researchers have recently noted some troubling trends in these CDC estimates.

Reporters at FiveThirtyEight and The Trace have issued multiple stories raising questions about the CDC’s estimation methodology and the accuracy of its data. In their most recent piece on CDC’s gun injury data, Sean Campbell and Daniel Nass write, “According to the CDC’s most recent figures, somewhere between 31,000 and 236,000 people were injured by guns in 2017. That range, which represents the confidence interval — the high and low ends of a range of estimates that probably contains the real number, whatever that number is — is almost four times wider than the one given in the agency’s 2001 estimate.”

In the same article, David Hemenway, the director of the Harvard Injury Control Research Center, is quoted as saying, “When I looked at the 2017 numbers, I went, ‘Oh, my god.’ You just can’t use those numbers.” Similarly, Guohua Li — who’s identified as “the editor-in-chief of the medical journal Injury Epidemiology and director of Columbia University’s Center for Injury Epidemiology and Prevention — adds, “I would not cite these estimates. As an editor, I would not publish any manuscript that is based on these estimates.”

What’s driving this? Unlike CDC’s gun fatality data, which counts figures from death certificates, CDC’s gun injury data samples a small number of hospitals (only 60 in 2017) to extrapolate estimates on gun injury data. Using such a small sample has resulted in the CDC’s nationwide estimate becoming “unstable.” Their ever-widening confidence interval has made using this data as the basis for our understanding of gun violence irresponsible.

In the past, Brady has averaged the five most recent years of gun violence data from the CDC in order to estimate the number of yearly and daily gun deaths and injuries in the U.S. These averages were used both for internal purposes and by external sources when quoting statistics on the gun violence epidemic in this country.

Given the unreliability of the CDC’s gun injury data, however, Brady will no longer be using the CDC’s gun injury estimates.

Instead, we’ll base our gun injury numbers on reliable data from the Healthcare Cost and Utilization Project (HCUP). The HCUP uses data from more than 950 hospitals to create its own gun injury estimate, which contains much less uncertainty than the CDC’s. As such, HCUP data gives a much more accurate representation of gun violence in the United States.

While we continue to average the five most recent years of gun fatality data from the CDC, Brady now averages the three most recent years of gun injury data from emergency department visits (2013, ’14, and ’16) available via the HCUP’s online query system. We now have greater confidence in our nonfatal gun violence statistics and better data for our organization, for the rest of the gun violence prevention movement, and for the American public to use to more accurately understand gun violence in America.

We are committed to being a leader in evidence-based solutions, and that starts with providing the best baseline to represent the scope of the problem. I encourage you all to read Brady’s recently updated numbers pertaining to this issue and, most importantly, to work with us on Brady’s multipronged approach to ending such this complicated and deadly epidemic. Americans deserve better.