Analysis of firearm deaths shows how gun violence differs across the U.S.

A study examining county-level changes in firearm deaths across the United States shows wide variation in trends and pronounced “hotspots” that unexpectedly improved or deteriorated over time.

The analysis of more than one million deaths over three decades found notable increases in gun suicides in counties in the west and mid-west and increases in gun homicides in counties in the south-east.

The study’s authors said the disparities may be becoming greater over time, as increases were often concentrated in regions that already had high gun death rates.

The paper by researchers at the University of Pennsylvania, led by Michelle Degli Esposti, is published in JAMA Network Open.

Using restricted access data from the National Vital Statistics System, the study examined firearm mortality data from 3111 counties in 49 states and the District of Columbia. Alaska was omitted due to frequent county boundary changes during the study period.

Examining two five-year periods, 1989–1993 and 2015–2019, researchers used advanced modeling to predict rates in the 2015–2019 period, and then identified counties showing unexpected decreases and increases over time.

Overall, rates of gun suicide increased, and gun homicide decreased between the time periods, however, these trends varied widely by region.

“The west and mid-west showed the most pronounced increases in firearm suicide rates, while the south-east showed localized increases in firearm homicide rates, despite the national decreasing trend,” the authors wrote.

“The across county variation we found in this study shows that the burden of gun suicides and homicides is not felt equally throughout the US,” said Dr. Degli Esposti. “This suggests that there are a number of local level factors at play which shape how likely a gun death is in a specific area. By looking to these striking local differences, we might be able to better understand why some counties show promising improvements, yet others show concerning deteriorations, in firearm deaths over time.”

Many hotspots showing unexpected increases in firearm homicide were clustered in the south and south-east, particularly in urban counties of Alabama, Mississippi, and Georgia.

Baltimore City in Maryland consistently emerged as a critical hotspot, where homicide rates almost doubled from 1989 to 2019. Generally, counties with unexpected increases in homicide were poorer, had higher unemployment rates, and lower median incomes.

Outliers for total firearm deaths and homicide deaths also had more federal firearm licenses per capita.

Large decreases were seen in the District of Columbia, which had the highest firearm homicide rate in the earlier time period (1989-1993) but decreased four-fold by 2015–2019. The New York counties of Bronx, New York, and Kings also saw large drops in firearm homicide rates.

Higher rates of gun suicides were clustered in rural regions in the west and mid-west, while decreases were seen in Nevada and South Dakota.

Outliers for increases in suicide rates were predominantly White and rural and had poorer access to level 1 trauma centers. Researchers said the information could help authorities understand factors leading to local surges in deaths and develop targeted responses.

“Our findings indicate that disparities between counties and regions may be becoming more exacerbated over time”, the authors wrote, saying the findings underlined the need for local interventions to prevent greater health disparities.

The study was funded by the National Collaborative on Gun Violence Research. The other authors are Jason Gravel, Elinore J. Kaufman, M. Kit Delgado, Therese S. Richmond, and Douglas J. Wiebe.