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Invited Commentary
Public Health
July 27, 2018

Fighting Unarmed Against Firearms

Author Affiliations
  • 1University of Colorado, Denver, Schools of Public Health and Medicine, Denver
  • 2Denver Health Medical Center and University of Colorado, Denver, School of Medicine, Denver
JAMA Netw Open. 2018;1(3):e180845. doi:10.1001/jamanetworkopen.2018.0845

Firearms caused 116 414 nonfatal injuries and 38 658 deaths in 2016 in the United States.1 After a decline in the 1990s, sustained throughout the 2000s, firearm-related suicide and homicide rates are increasing.1,2 The case-fatality rate ranks among the highest at 30%, ie, 1 in 3 individuals injured by firearms dies.1 It is one of the few such lethal conditions for which there is a single, known, avoidable cause. Moreover, it is the only such lethal condition for which there is a controversial congressional ban on funding. The 1996 ban, known as the Dickey Amendment, does not target research itself but advocacy efforts. Yet it has successfully stifled the funding stream for research.3 It has discouraged scientists from pursuing careers investigating firearm-related issues because of intense controversy, lack of prestige, and academic fatigue. This will compromise the field’s future, as few mentors will feel prepared to encourage or nurture academic development in this area. A domino effect will ensue that we may not have funding to gauge.

Braga and Cook4 present their study of caliber as a determinant of death in firearms assaults, funded by a US Bureau of Justice Assistance grant. It is commendable that the grantor allocated funds to obtain scientific evidence in such a relevant, yet politically charged topic. The researchers used a data set from the files of the police department of Boston, Massachusetts, and enriched it by interviewing investigators and reviewing incident and detective case files and reports from emergency management services and coroners. This research followed up a 1972 study by Zimring, who proposed that “if attacks with different types of firearms have significantly different death rates, this lends important support to the theory that effective weapon controls can influence the homicide rate.”5 Similar to work of Braga and Cook, Zimring’s study suggested that large caliber was a determinant of firearm-related death. Collectively, these results posed the possibility of preventing firearm-related fatalities by modifying access to large-caliber weapons rather than by influencing individual behavior and intentionality.

Although Braga and Cook4 focused their conclusion on caliber as a determinant of death, their investigation illustrated the multifactorial pathogenesis of gun-related deaths. Multiple factors were associated with death and likely modified the effect of other predictors on survival. For example, it is likely that the region of the body wounded, number of wounds, and caliber interacted.

Caliber corresponds to the bullet’s outer diameter and was traditionally reported in inches but has more recently been reported in millimeters, particularly for military weapons. Caliber is a potential factor in determining tissue damage in gun-related trauma, but, contrary to common beliefs, is not the most important.6 The bullet’s capacity to disrupt tissue is best estimated by the kinetic energy (KE = 1/2 mass × velocity2) imparted by the bullet, measured in foot-pounds (ft-lb). Consequently, bullet velocity is much more important than mass. For example, a 0.22-caliber handgun (0.22 in [5.59 mm]) has a caliber similar to the AR-15 assault rifle (0.223 in [5.66 mm]), but the latter has a vastly larger destruction power (a handgun firing a 100-grain bullet at 1000 ft/s yields a KE of 100 ft-lb, whereas an AR-15 firing a 55-grain bullet at 3250 ft/s yields a KE of 1300 ft-lb). Furthermore, high-velocity (>2500 ft/s) bullets produce tissue destruction beyond their direct pathway because of the bullet’s instability on striking tissue, provoking the bullet’s deviation, fragmentation, and sometimes cavitation.6 Even handguns with similar caliber have different damage potential. For example, 0.38-caliber revolvers, used by police in the 1960s and 1970s, produce less KE (220 ft-lb) than the 0.357 magnum (624 ft-lb) because of the propellant amount, despite a larger caliber.6 In fact, the well-known 0.45 Colt has a muzzle energy of only 250 ft-lb. Braga and Cook4 accounted for this variation by classifying the rifle-related homicide (caliber, 0.30 in [7.62 mm]) as large caliber even though its actual caliber (0.30) is smaller than most weapons classified as medium caliber. The bullet mass, propellant, jacket, and other characteristics of the bullets also play significant roles in wounding potential.

The distance between a gun and its target influences survival, as the bullet’s KE decreases with distance traveled after firing. Indeed, the increased odds of death in indoor vs outdoor shootings in Braga and Cook’s study is in line with the likely longer distance traveled by bullets in outdoor shootings. Also shown in the study, the number of wounds (“rounds on target”) is associated with survival. However, number of wounds is not independent from caliber, as small-caliber weapons may allow more bullets to be shot with precision (ie, “on target”) and within a shorter period. This underscores the deadly nature of assault rifles, especially the civilian version of the AR-15 used in several mass shootings in 2017 and 2018, which can carry large-capacity magazines that permit shooting 30 or more bullets without reloading.7 Indeed, increases in number and severity of wounds have been implicated in the upward trend in the case-fatality rates of gunshot wounds in recent years.8 In addition, human tissues vary in how easily they are damaged by bullets.

Several data sources are needed to understand the complexity of circumstances involved in firearm injuries. Ideally, police reports should be merged with clinical data sets. Notwithstanding the difficulties for such an undertaking posed by patient confidentiality, some of the existing clinical data sets suffer from low quality. Indeed, Thiels et al9 showed that clinical data missingness was much greater in firearm incidents compared with other injuries in the National Trauma Data Bank, a national repository of trauma-related hospital data. Lack of personnel prepared to gather information in the sensitive circumstances surrounding gun-related episodes is likely a major culprit.

The lack of information, low-quality data, and the difficulties in merging data sets from different sources (police, legal, behavioral, medical, coroner, etc), compounded by scarce funding and public controversy, demoralize scientists who could provide evidence to inform policy and increase public awareness. Jay Dickey, the House representative who proposed the Dickey Amendment, reversed his position on gun-related research following the mass shooting in Aurora, Colorado, in 2012. In an eloquent 2012 Washington Post editorial (written in partnership with Mark Rosenberg, former director of the Centers for Disease Control and Prevention’s National Center for Injury Prevention and Control, who opposed the amendment in 1996), Dickey called for research funding for firearm death prevention: “The same evidence-based approach that is saving millions of lives from motor-vehicle crashes, as well as from smoking, cancer and HIV/AIDS, can help reduce the toll of deaths and injuries from gun violence.”10

Guns do not kill people; neither do cigarettes, cars, motorcycles, fast food, alcohol, drugs, or sweetened beverages. In contrast to guns, however, our society strongly supports research in preventing the adverse effects linked to these other risk factors. Moreover, we endorse rigorous enforcement of evidence-based medical counseling, required warnings, safety devices, tax increases, age limits, and strict regulations to diminish their damage. We, as a society, must encourage and support scientists, such as Braga, Cook, and others, who, despite the lack of resources, remain dedicated to those affected by the increasing power of firearms.

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Article Information

Published: July 27, 2018. doi:10.1001/jamanetworkopen.2018.0845

Open Access: This is an open access article distributed under the terms of the CC-BY License. © 2018 Sauaia A et al. JAMA Network Open.

Corresponding Author: Angela Sauaia, MD, PhD, 1880 S Xenia Ct, Denver, CO 80231 (angela.sauaia@ucdenver.edu).

Conflict of Interest Disclosures: Dr Moore reported grants from Haemonetics, Instrumental Laboratory, and Prytime during the conduct of the study. No other disclosures were reported.

Centers for Disease Control and Prevention. WISQARS (Web-Based Injury Statistics Query and Reporting System). https://www.cdc.gov/injury/wisqars/. Updated May 3, 2018. Accessed April 15, 2018.
Lawless  R, Moore  EE, Cohen  MJ, Sauaia  A.  Increasing violent and unintentional injuries—national trends 2000-2016.  JAMA Surg. In press.Google Scholar
Stark  DE, Shah  NH.  Funding and publication of research on gun violence and other leading causes of death.  JAMA. 2017;317(1):84-85. doi:10.1001/jama.2016.16215PubMedGoogle ScholarCrossref
Braga  AA, Cook  PJ.  The association of firearm caliber with likelihood of death from gunshot injury in criminal assaults.  JAMA Netw Open. 2018;1(3):e180833. doi:10.1001/jamanetworkopen.2018.0833Google ScholarCrossref
Zimring  FE.  The medium is the message: firearm caliber as a determinant of death from assault.  J Legal Stud. 1972;1(1):97-123. doi:10.1086/467479Google ScholarCrossref
Rhee  PM, Moore  EE, Joseph  B, Tang  A, Pandit  V, Vercruysse  G.  Gunshot wounds: a review of ballistics, bullets, weapons, and myths.  J Trauma Acute Care Surg. 2016;80(6):853-867. doi:10.1097/TA.0000000000001037PubMedGoogle ScholarCrossref
Moore  EE. The Parkland shooter's AR-15 was designed to kill as efficiently as possible. NBC Think. February 15, 2018. https://www.nbcnews.com/think/opinion/parkland-shooter-s-ar-15-was-designed-kill-efficiently-possible-ncna848346. Accessed April 28, 2018.
Sauaia  A, Gonzalez  E, Moore  HB, Bol  K, Moore  EE.  Fatality and severity of firearm injuries in a Denver trauma center, 2000-2013.  JAMA. 2016;315(22):2465-2467. doi:10.1001/jama.2016.5978PubMedGoogle ScholarCrossref
Thiels  CA, Zielinski  MD, Glasgow  AE, Habermann  EB.  The relative lack of data regarding firearms injuries in the United States  [published online August 8, 2017].  Ann Surg. doi:10.1097/SLA.0000000000002471PubMedGoogle Scholar
Dickey  J, Rosenberg  M. We won’t know the cause of gun violence until we look for it. Washington Post. July 27, 2012. https://www.washingtonpost.com/opinions/we-wont-know-the-cause-of-gun-violence-until-we-look-for-it/2012/07/27/gJQAPfenEX_story.html?utm_term=.6d1ed0d3edb3. Accessed April 28, 2018.
4 Comments for this article
Restricting Handgun Calibers
Michael Keyes, MD |
The editorial comments by doctors Sauaia and Moore represent the somewhat simplistic and cognitively biased response seen often in dealing with the subject of gun violence by persons who are not familiar with the complexities of the issue or have no interest in dealing with them.

I agree with the conclusion that more research should be done about murder in this country, for example the prescriptions promoted by them are not based on fact, just opinion, and the analysis offered by them is tainted by lack of technical knowledge (basically everything they said about firearms is wrong - it's
22 caliber in the US, 38 Special and 357 Magnum have the same diameter, etc.) and lack of familiarity with the demographics and causes of violence in general. In addition, two thirds of handgun deaths are by suicide, makes the 1 in 3 death statistic wrongheaded at best or deceptive at worst.

Suicide by deadly means has an entirely different dynamic from gang violence, domestic disputes and the actions of school shooters, but instead of offering an analysis that is based on already available information, they choose the simplistic low hanging fruit.

More research is needed. The Obama era study by the National Science Foundation (https://www.nap.edu/read/18319/chapter/3) in 2013 called for a more sophisticated look at the problem based on current (then) knowledge than either author suggests. I think we can do better than banning certain calibers (which the authors got wrong to begin with) or their other tired suggestions.

While this approach is low hanging fruit, it has the effect of continuing the polarization that permeates this issue. Gun owners who are contemplating suicide will be adverse to such draconian (and illegal) measures before problems occur and will not pay attention. Those five or six urban counties where most of the murders and mass shootings occur already have stricter rules than the rest of the country (very similar to what is being proposed) which does not seem to be helping. We need more sophisticate and probably more expensive ways to deal with this subject than caliber restriction.
Missing Data
Greg Kevans, B.S. Computer Science | None
I must agree with Dr. Keyes' comments, and I was quite disappointed that the authors repeated the predictable conflation of suicide events with homicide events. But as an engineer I found them to be very remiss in neglecting any mention of the involvement of ball ammunition versus hollow point in their sample populations. This is a major factor in wound consequence and every physician should appreciate the physics of these projectiles. In general, ball ammunition can penetrate more deeply to major vessels while hollow point projectiles expend their energy more rapidly with less penetration but usually more cavitation. There are so many variables in gunshot consequences that should be considered, and it is regrettable that the authors focused on caliber size (with quite a few errors, as Dr. Keyes has noted) as a primary variable that they use to conclude "effective regulation of firearms could reduce the homicide rate." The "effective" regulation in cities such as Chicago and Baltimore has had a spectacularly unimpressive effect on the reduction of chronic homicide rates in specific geographic areas of these cities.

Firearms: Public Health Threat
Arthur Palamara, MD | University of Miami, Miller Shool of Medicine
There is an incontrovertible body of evidence that concludes that the unfettered availability of firearms is harmful to society. The larger and quicker firing the weapon, the more carnage it produces. To its enormous credit, the AMA House of Delegates recognized this relationship in June 2018 and adopted policies to advocate for restrictions on the sale and type of firearms and education of their owners. 

These policies are both logical and the moral obligation of an organization that is dedicated to the betterment of public health and desirous of reducing the >100,000 annual gun injuries and ~ 40,000 deaths.

Ernest M Kraus, BS pharm | Registered Pharmacist

A gun is there for protection whether it be the private citizen or law enforcement. With practice, any one can go on a shooting range and hit the target. It is another issue when confronted with deadly force from one intent on doing you harm; that is why there are so many spent casings at most scenes. Size does matter: as you increase the caliber you increase the recoil which now requires aiming and sighting before firing. Ernest M. Kraus, RPh