THURSDAY, Sept. 12 (HealthDay News) -- The more gun owners in a state, the higher its rate of gun-related murders, according to a new study.
The findings appear to challenge the National Rifle Association's claim that higher levels of gun ownership do not lead to increased gun violence.
Researchers analyzed data collected in all 50 states between 1981 and 2010 and found a "robust correlation" between estimated levels of gun ownership and gun-related murders at the state level, according to the study, which was published online Sept. 12 in the American Journal of Public Health.
After controlling for other factors associated with murders, the researchers concluded that for each 1 percent increase in gun ownership, there was a 0.9 percent increase in a state's gun-related murders.
All other factors being equal, for instance, the findings suggest that if the gun ownership estimate for Mississippi was 58 percent (the average for all states) instead of 77 percent (the highest of all states), its gun-related murder rate would be 17 percent lower, the study authors said.
"Understanding the relationship between the prevalence of gun ownership -- and therefore the availability of guns -- and firearm-related mortality is critical to guiding decisions regarding recently proposed measures to address firearm violence," wrote Dr. Michael Siegel, a professor of community health sciences at the Boston University School of Public Health, and colleagues.
This is believed to be the largest study conducted to date into the link between gun ownership and firearms violence, and the first to comprehensively examine the issue since the shooting last December of 20 children and seven adults at Sandy Hook Elementary School in Newtown, Conn.
"In the wake of the tragic shooting in Newtown, Conn., last year, many states are considering legislation to control firearm-related deaths," Siegel said in a Boston University Medical Center news release. "This research is the strongest to date to document that states with higher levels of gun ownership have disproportionately large numbers of deaths from firearm-related homicides. It suggests that measures which succeed in decreasing the overall prevalence of guns will lower firearm homicide rates."
Although the study found an association between the number of gun owners in a state and its rate of gun-related murders, it did not establish a cause-and effect relationship, the researchers said.
The findings are consistent with previous studies that found an association between higher levels of gun ownership and higher gun-related murder rates, the researchers said.
The new study found that gun ownership levels during the three-decade study ranged from a low of about 26 percent in Hawaii to a high of nearly 77 percent in Mississippi. Gun-related murder rates ranged from a low of 0.9 per 100,000 people in New Hampshire to a high of nearly 11 per 100,000 in Louisiana. The average for all states was four gun murders per 100,000 people.
A positive finding emerged: The average gun-related murder rate for all states fell from 5.2 per 100,000 in 1981 to 3.5 per 100,000 in 2010.
You can learn more about preventing gun violence at the Brady Campaign to Prevent Gun Violence.