Researchers suggest that new, more powerful weapons are part of the reason gunshot wounds are more deadly. Above, a newly assembled AR-15 rifle at Stag Arms in New Britain, Conn.

(AP Photo/File)

Victims of gunshot wounds in Denver are more likely to die than they were a decade ago, according to researchers at the Colorado School of Public Health. 

Researchers studied victims of gun violence treated at Denver Health Medical Center, the city's largest trauma center, between 2000 and 2013.

The findings are in a recent issue of the Journal of the American Medical Association.

Researchers found that gunshot wounds are larger now than a decade ago and penetrate more deeply into the body. The findings also show the number of gunshot wounds per victim increased.

Dr. Angela Sauaia, a professor and the lead researcher for the study, says it's difficult to know exactly why the nature of gun violence has changed because Congress has discouraged the Centers for Disease Control and Prevention from funding research on guns. But she believes it has to do with the kinds of guns being used and the way they are being used.

The American Medical Association recently voted to urge Congress to pay for more research.

Sauaia spoke with Colorado Matters host Ryan Warner. Read the transcript below:

Ryan Warner: This is Colorado Matters from CPR News. I'm Ryan Warner. Gunshot wounds are deadlier than they were a decade ago. Researchers studied victims of gun violence back to the year 2000. All were patients at Denver Health Medical Center. The new findings are in the Journal of the American Medical Association. Dr. Angela Sauaia is lead researcher. She's at CU's Anschutz Medical Campus and joins us via Skype. And thanks for being on the program. 

Dr. Angela Sauaia: Thank you very much, Ryan.

Warner: How are gunshot wounds getting deadlier?

Sauaia: Well, they're getting deadlier because the injuries they cause are becoming more serious and because they're becoming more numerous. So a patient arriving today with gunshot wounds in the emergency room will have more severe injuries and will have more injuries that are much more difficult to treat than ten years ago.

Warner: That is to say they're simply coming in with more bullet wounds and those bullet wounds are what, are they larger? Are they more penetrating?

Sauaia: Both. We have several ways to measure the severity of wounds. How much each organ, so not just the wounds you see, but what happens inside the body of the patient, so injuries to the lungs, to the heart, the liver, to the spleen, to the kidneys and so forth, and especially vascular injury, injuries to the vessels that carry your blood. And we know that the size of these injuries has become bigger, so more of your liver has been destroyed. More of your kidney has been destroyed. More of your heart has been destroyed. The second thing we are noticing, and actually that was what motivated the study, is the patients arriving with multiple bullets and injuries in the brain and the heart and the pelvis, and you can imagine how many teams of physicians you need to treat all those injuries in separate parts of the body, not to mention their effect together is different than their separate effect. 

Warner: So you need specialists to address a particular organ or a particular part of the body, and all of this, you say, is making gunshot wounds deadlier. Let's explore first how much more deadly over the last decade.

Sauaia: They are becoming about six percent deadlier every two years. Every couple years, they go up six percent since the year 2000.

Warner: Since 2000. And the size of the wounds, how much are those increasing?

Sauaia: Well, that varies a lot. It's not useful clinically to give you a number. And I'm not trying to run away from the numbers. We do have numbers, but they mean different things for different organs. A tiny little hole in the brain can make a lot more damage than a big hole in your leg. Do you see what I'm saying?

Warner: I do.

Sauaia: So size does not matter here. 

Warner: But the number of bullet wounds, I imagine, does. And what has been the increase there? Because you say that patients coming into Denver Health more often have multiple wounds.

Sauaia: Yes, we just got a patient a few weeks ago with six bullet wounds, and that does not surprise any trauma surgeon now. We used to have a patient who would arrive with one or two gunshot wounds, that was ten years ago. Now they arrive to six, seven bullets.

Warner: The obvious question here is why all this is true, does it have to do with the guns themselves? The people shooting the guns? The ammunition in them? What can you say?

Sauaia: Well, I can say two things about that. The first is we're going to go in the area of speculation and, as a scientist, I don't like too much to go for speculation. There is a profound desire, from all researchers, to get the data that will respond your question exactly. I would be able to tell you what type of gun, what type of magazine capacity, if there was more than one perpetrator involved. These kind of data are very difficult to find. Now talking to trauma surgeons across the country, they will all tell you that they know exactly what's happening. We have guns that are much more dangerous now, because they have a higher magazine capacity. The ability to shoot multiple times without any time in between the shots makes them incredibly dangerous. 

Warner: But as you say, that's a hypothesis. Do you have others?

Sauaia: Well, I think the fact that we have more people buying guns, so purchase of guns has increased over time. Purchase of more powerful guns has increased over time, have something to do with it.

Warner: When you talk about more powerful guns, are you hinting there at what have been called 'assault weapons'; weapons that used to be banned, but then that ban expired.

Sauaia: Mm-hmm. That's exactly what I'm talking about. I'm talking about guns that have the ability to shoot multiple times, and, as we saw in the tragic incident in Orlando, which is just one incident in multiple incidents in the last few years. They are increasing by an incredible amount. Nobody would be able to harm this many people with the same gun they use to kill an elk.

Warner: So you have talked to us about the fact that gunshot wounds, at least those studied at Denver Health, have become more lethal. And at the same time, I think of advances in medicine that would presumably mean doctors could keep patients alive. Why isn't that the case?

Sauaia: That's a very astute question, and I think that's exactly why our group wanted to study all the injuries, all the traumatic injuries, not just firearms. We wanted to know if, for other injuries, how well we were able to treat them. And if you look at the graph of the study we just published in JAMA, it's a very clear trend. All the other injuries, motor vehicle accident, pedestrian accidents, bicycle injuries, you know name it, motorcycles. Anything is going down. So we are, indeed, being able to save many more lives. What we can't do is to outpace the advancements in the dangerous effects of guns. You see, we do everything we can to make cars safer. Firearms work in the exact opposite direction. Technology makes them more likely to injure, not less likely.

Warner: But isn't that what I want if I'm a gun owner? To protect myself? I don't want something that just inflicts a little bit of harm to someone trying to hurt me. I want them dead.

Sauaia: I'm not sure what you would want as a gun owner, but we have plenty of studies showing that it's a very rare fact that somebody who possesses a gun was saved by their own gun.

Warner: Well on the subject of research, in 1996, congress essentially barred the Centers for Disease Control and Prevention from putting money into studying gun violence. The president lifted that ban, President Obama, but congress has blocked funding. The American Medical Association recently came out in favor of funding research. In what ways have you run up against that?

Sauaia: We actually planned this study when we started two years ago as a statewide study, and we couldn't do it. There was so much red tape to obtain data that we could merge with the death records that we ended up reducing the study to just the Denver area, thanks to the willingness of Denver Health to provide their data so openly. Of course, other studies have shown this, in Newark and other locations across the states showing that Colorado is no different, and Denver's probably just a small picture of what's happening in other parts of the country.

Warner: And how does that relate to the federal stance on gun research and on funding it?

Sauaia: That's a, that's another astute question. I have young colleagues who are very motivated to study firearm injuries, and they have confessed to me, as a senior researcher, that they prefer to not go into that path because it's so difficult to obtain the data, and there is very little funding available from federal agencies to fund their time while they try to work out the red tape that involves getting data on firearm injuries. If I am going to construct the databases we need, we're going to have to face lots of issues regarding to confidentiality, protecting patients' identity in this type of investigation, so this takes time, precious time. This time needs to be funded, so we can make a living. That's --

Warner: And what is the nature of the data that you're missing? Can you be more specific about what you'd like to get your hands on?

Sauaia: I would like to get my hands on the type of gun you're using, the size of the magazine capacity, the caliber of the bullet, and the situation where that happened, where there are more than one perpetrator. So is this a behavioral thing that we should be working on? It's not our suspicion. We suspect it's related to the gun itself, not to behaviors, but of course there's somebody behind the gun  shooting it.

Warner: Couldn't you get that from police reports?

Sauaia: I wish. But think about it, if I want the data from the police, I'm going to have to request the data from the police with the identification so I can merge that with the medical record. In the minute you're asking for people's identities, we have to do a lot of procedures. That's a good thing. It's not a bad thing. We should have to have lots of procedures to obtain people's identities. But that takes time and a lot of work and for the state, I wasn't able to obtain permission to merge death records with medical records.

Warner: There might be some listening who think, it's not right to look at the gun. It's right to look at the person shooting the gun. That is, people kill people, guns don't kill people. What would you say to them?

Sauaia: I would say that people with no guns do not kill people. People with no guns cannot give gunshot wounds to anybody.

Warner: Thanks so much for being with us.

Sauaia: Thank you so much for having me.