More gun laws reduce violent deaths. Or do they?

Research on gun violence is staging a roaring comeback in the nation’s leading medical journals, with a study published this week linking the strength of states’ gun laws to varying rates of gun violence across the United States.

The new study, published “Online First” by JAMA Internal Medicine, looked at rates of violent deaths over four years -- from 2007 to 2010 -- and looked at how their distribution related to the patchwork of state laws governing gun ownership. It found that in those states with the most restrictive gun laws, rates of violent deaths were significantly lower than in those that had the least stringent laws on their books.

When it looked at gun deaths by suicide, the study found a particularly deep divide between stringent-gun-law states and states with few restrictions in gun laws: Compared with states that had a “legislative strength score” in the top quartile of restrictiveness (they have between nine and 24 gun control laws on their books), those states with a legislative strength score in the bottom quartile (having zero to two gun-control laws on their books) had on average 6.25 more gun suicides per 100,000 people.

The gap in homicide deaths between states with most-restrictive and least-restrictive gun laws was far narrower. In the most restrictive states, there was on average one fewer gun-related homicide for every 250,000 people.

A commentary on the study, also published “Online First” in JAMA Internal Medicine, said that as scientific research and as a guidepost to policymaking on guns, the study has major shortcomings and that its findings were unclear.

Gun violence expert Dr. Garen Wintemute wrote that the key measure of states’ laws -- the legislative strength score -- hasn’t been proved reliable and meaningful. The study treats all gun laws as if they should have equal impact, he added. The authors, he wrote, fail to take into account the flow of guns across state borders, or the fact that states with restrictive laws probably have lower rates of gun ownership.

Because gun laws are largely designed to prevent or deter the criminal use of guns, the study’s most notable findings -- linking gun laws to reduced suicides -- makes no sense, wrote Wintemute, an emergency physician and director of UC Davis’ Violence Prevention Research Program.

The authors, wrote Wintemute “did well with the data available to them.” But in the end, they can provide “no firm guidance” about which gun laws work to reduce violence and how.

In bemoaning the quality of data and research on gun violence, Wintemute turned both barrels on the firearms industry and its allies in Congress. Though such research was thriving into the early 1990s, lawmakers working with the National Rifle Assn. spearheaded an effort to “choke off the production of the evidence” that could be used to craft effective violence-reduction policy, he wrote.

Those efforts to cut off federal funds for research succeeded, and “when rates of firearms violence were at historic highs and appeared to be increasing, the government abandoned its commitment to understanding the problem and devising evidence-based solutions,” Wintemute wrote.

Since the shootings in Newtown Conn., that claimed 28 lives, and the mass shootings across the county that claimed 58 lives in 2012, physicians and public health researchers have grown increasingly vocal about their role in shaping policy -- including gun measures -- that will reduce violent injuries and deaths. In the journals published by the American Medical Assn., these are the fourth and fifth articles to address gun violence.

But “with almost no funding for firearm violence research, there are almost no researchers,” Wintemute wrote.

For now, that may mean there’s more commentary than solid research to publish in the nation’s leading medical journals. “Until we revitalize firearms research, studies using available data will often be the best we have. They are not good enough,” Wintemute wrote.

By the way, states in the top quartile of “legislative strength” were: Massachusetts, California, New Jersey and Connecticut, New York, Hawaii, Maryland, Rhode Island, Illinois, Michigan and Delaware. In the bottom quartile were Utah, Oklahoma, Louisiana, Kentucky, Alaska, Idaho, Arizona, West Virginia, South Dakota, New Mexico, North Dakota, Missouri, Kansas and Arkansas.