More guns means more gun deaths, according to a study comparing gun ownership and fatalities among 27 developed nations. The report was published online Sept. 18 in the American Journal of Medicine.
There is "a significant, positive correlation between guns per capita per country and the rate of firearm-related deaths" (r = 0.80; P less than .0001). On linear regression, gun ownership was a strong and independent predictor of firearm mortality (P less than .0001), wrote Dr. Sripal Bangalore of New York University and Dr. Franz Messerli of Columbia University, both in New York.
"Although correlation is not synonymous with causation, it seems conceivable that abundant gun availability facilitates firearm-related deaths ... the [finding] debunks the widely quoted hypothesis ... that countries with higher gun ownership are safer than those with low gun ownership," they said.
The team didn’t find a significant correlation between guns per capita and national crime rates, which argues "against the notion of more guns translating into less crime," they said (Am. J. Med. 2013 Sept 18).
Mental illness correlated weakly with firearm deaths (r = 0.52, P = .05), and did not correlate with national crime rates.
"In having almost as many guns as it has people, prevalence of private gun ownership was the highest in the [United States]" at 88.8 guns/100 people; the United States also had the highest firearm death rate at 10.2/100,000. In contrast, Japan, with the lowest gun ownership rate of 0.6/100 people, had the lowest rate of firearm-related deaths at 0.06/100,000, the researchers wrote.
In addition to the United States and Japan, the study included Canada, Australia, and most European nations, among others. Data on gun ownership was culled from the 2007 Small Arms Survey; national firearm-related death figures came from the World Health Organization and other sources; and crime rates were pulled from the United Nations Surveys of Crime Trends. National rates of major depressive disorder – also from the World Health Organization – were used as proxies for a country’s mental illness burden.
"Others have suggested that violence is often due to the perpetrator’s mental illness and therefore, lack of treatment for mental illness may be more of a pressing problem than mere availability of guns. [Although] there is little question that the combination of mental illness and easy access to guns may prove to be synergistic in their lethality ... the predictive power of mental illness burden was of borderline significance," the authors noted.
The study was an attempt to inject evidence into the gun control debate. Although "the association between gun ownership, mental illness, and firearm-related deaths has been hotly debated ... many of [the] arguments from both sides are based on little or no evidence," they said.
The study was published early following the Sept. 16 shootings at the Washington (D.C.) Navy Yard. Several doctors’ groups have repeatedly called for gun control, including the American Academy of Family Physicians, American Academy of Pediatrics, and American College of Emergency Physicians.
The investigators have no financial disclosures. Their project received no external funding.