In public health, there are totals which can give researchers and policy makers a raw sum of cost or human loss. There are per capita counts, which allow for more meaningful comparisons of an issue’s frequency across population groups and geographic boundaries. And thanks to a research scientist named Francis Boscoe, there is another metric, known as “distinctive causes of death.” Calculating the difference between state and countrywide averages for the same sources of fatalities, it zeroes in on the killer claiming lives at a rate most out of whack with the national norm.

In nine states, that disproportionate killer is guns.

The finding comes from an analysis by Stateline, the media arm of the Pew Charitable Trusts, which crunched the 2014 data (the most recent available) on 113 separate causes of death identified by the Centers for Disease Control and Prevention.

Five of the states where shootings represent an unusually common source of fatalities have firearm homicides as their distinctive cause of death. Two of those states, Louisiana and Mississippi, tally gun homicide rates three times higher than the national average. A third, South Carolina, records a rate almost twice as high.

The other four states — Alaska, Idaho, Montana, and Wyoming — have firearm suicides as their distinctive cause of death.

cause-of-death-guns-and-overdoses

To Catherine Barber, who directs the Means Matter Campaign at the Harvard School of Public Health’s Injury Control Research Center, the explanations for the disproportionate rates of gun deaths recorded in nearly a fifth of the country are simple: “The states with high gun ownership have more gun deaths — a lot of it is gun availability,” she tells The Trace. “Some of it is also race.”

Citing the most recent CDC statistics, Barber points out that the firearm homicide rate for blacks is 15 out of 100,000, while for whites it’s one out of 100,000. Where a large portion of the population is black, the homicide rate is higher,” she says. “It’s just outrageous.” Blacks make up 37.5 percent of Mississippi’s population, 32.5 percent of Louisiana’s, and 28 percent of South Carolina’s, compared to 13.2 percent for the U.S. as a whole.

A new New York Times breakdown of multiple casualty shootings emphasized the racial disparity in fatal shooting victims. “Every time we look at the numbers, we are pretty discouraged, I have to tell you,” one criminologist told the paper.

Where the distinctive cause of death is gun suicides, the numbers also show much larger than usual shares of residents owning guns. Researchers led by epidemiologists at Columbia University calculated last year that Alaska, Idaho, Montana, and Wyoming placed in the top six for state gun-ownership rates. At 62 percent and 57 percent, respectively, Alaska and Idaho are double the national gun ownership rate of 29 percent that the researchers used as a baseline.

The lethality of guns means that people who attempt suicide with them are more likely to succeed than those using other means.

“Most people who become suicidal don’t stay suicidal,” Barber says. “For those making quick decisions, it really matters what’s available to them. If all they’ve got is a bottle of Aspirin to swallow, they’re going to be a lot safer than if they’ve got a loaded gun right there.”

Boscoe told ABC News last year that he came up with distinctive cause of death metric as a way to call attention to public health issues that might not receive the attention they warrant. The new Stateline map provides an example of how that can play out. While the epidemic of fatal opioid overdoses is a serious crisis that has generated bipartisan legislation in Congress, this distinctive cause of death analysis shows that it is an outlier in 33 percent fewer states than gun fatalities.

[Photo: “Gun Country” by Michael Murphy. Image courtesy of the artist.]