Gunshot victims were nearly five times as likely to die when shootings involved large-caliber firearms than when small-caliber weapons were used, a study of over 500 such incidents found.
The analysis of Boston Police Department data revealed that shootings were more likely to result in death with both large-caliber (OR 4.54, 95% CI 2.37-8.70, P<0.001) and medium-caliber guns (OR 2.25, 95% CI 1.37-3.70, P=0.001) compared with small-caliber firearms, according to Anthony Braga, PhD, of Northeastern University in Boston, and Philip J. Cook, PhD, of Duke University in Durham, North Carolina.
And a simulation model revealed that gun homicides would be reduced by 39.5% if both medium- and large-caliber guns were replaced with small-caliber firearms, the authors reported in .
"This study was designed to test a foundational issue in the gun policy debate: whether the probability of death is connected to the intrinsic power and lethality of the gun deployed (guns do kill people) or simply a reflection of the shooter's intent (people kill people)," Braga told 51˶ in an email.
While homicide victims had a higher average number of gunshot wounds than survivors (2.82 [2.76] versus 1.67 [1.41]), the authors found that number of wounds was not statistically related to caliber in both fatal and nonfatal cases.
The study builds on , which showed the likelihood of death to be correlated with the caliber of the assailant's firearm, but with improved data and statistical measurement tactics. Most other reports, Braga said, do not analyze detailed data such as the gun used by the assailant, the number of wounds inflicted, and location of the attack.
"We wanted to pursue the study to provide more rigorous scientific evidence on the role played by the intrinsic power of the firearm deployed in criminal gun attacks on whether the victim survives or dies," said Braga.
In a that accompanied the study, Angela Sauaia, MD, PhD, and Ernest E. Moore, MD, both of the University of Colorado in Denver, said the fact the researchers were able to obtain the data sets from the Boston Police Department and publish the study was remarkable. Scarce funding and public controversy may lead many researchers away from pursuing this area of study, they wrote. Medical records of gun victims are sparse, and do not provide information about the type of gun used, the size of the magazine, or how many shots were fired.
"We have to have more funding because if we don't, there will not be well-collected data and well-conducted research," Sauaia told 51˶. "There has to be a change not just in the legislation regarding gun research but also in the culture, so that people who engage in this research will have the same opportunities as researchers who devote their time to diabetes, cancer, or other killers in our society."
The 1996 Dickey Amendment has long been viewed as effectively banning the CDC from conducting gun-related research, Sauaia and Moore noted, though the .
The study from Braga and Cook included 220 fatal and 291 nonfatal criminal incidents reported to the Boston Police Department from 2010 to 2014. Most homicide victims and survivors were young minority men (92.2% male, 80.8% black) with prior court arraignments. The majority of incidents involved gangs or drugs and took place in outdoor, disadvantaged Boston neighborhoods, according to police department investigations.
Caliber sizes were divided into three groups:
- Large (.357 magnum to 7.62 × 39 mm)
- Medium (.38 to 9 mm)
- Small (.22 to .32)
Of 93 shootings involving large-caliber firearms, 60 resulted in homicides and 33 were nonfatal. Small-caliber guns were used less frequently: of 61 shootings, 23 were fatal and 38 were not. The most common caliber used was 9 mm in both homicides (35.6%) and nonfatal shootings (27.2%).
Most characteristics measured, including race, criminal history, and circumstances of the shooting were similar across fatal and nonfatal cases. However, victims were more likely to die if they were shot indoors than outdoors (OR 2.55, 95% CI 1.79-3.64, P<0.001), likely due to the distance from which the victim was shot, the authors noted.
The caliber of gun was statistically independent of observable characteristics of the assault, including skill and intent of the shooter. Researchers controlled for the victims' demographic characteristics, circumstances and location of the assault, and number and location of wounds.
Some experts believe enhanced gun control would do little to change homicide rates due to the shooter's intent, though this is contrary to the current study's findings, Braga said. Citing a that asked experts if a policy that reduced the gun homicide rate would have an impact on the overall homicide rate, Braga said that those in favor of deregulation were more likely to believe the policy would not affect the overall homicide rate -- assailants would turn to other weapons.
The study is limited in that it only includes shootings reported to the Boston Police Department. Additionally, the caliber was not available in all of the police reports available and researchers did not study the statistical pattern of missingness within each of the two categories in fatal and nonfatal assaults.
Disclosures
Braga reported a grant from the U.S. Bureau of Justice Assistance.
Moore reported grants from Haemonetics, Instrumental Laboratory, and Prytime.
Primary Source
JAMA Network Open
Braga A, Cook P "The association of firearm caliber with likelihood of death from gunshot injury in criminal assaults" JAMA Network Open 2018;1(3):e180833.
Secondary Source
JAMA Network Open
Sauaia A, Moore E "Fighting unarmed against firearms" JAMA Network Open 2018;1(3):e180845.