Having a higher number of firearm laws in a state may be associated with a lower rate of firearm fatalities from suicides and homicides, according to a study of all 50 states published by JAMA Internal Medicine.

More than 30,000 people die annually in the United States from injuries caused by firearms.

Eric W. Fleegler, M.D., M.P.H., of Boston Children’s Hospital, Massachusetts, and colleagues analyzed firearm-related deaths reported to the Centers for Disease Control and Prevention using the Web-based Injury Statistics Query and Reporting System from 2007 through 2010.

They also examined state-level firearm legislation across five categories of laws to create a “legislative strength score.” The authors then used statistical analysis to measure the association of that score with mortality rates.

“In an analysis of all states using data from 2007 through 2010, we found that a higher number of firearm laws in a state was associated with a lower rate of firearm fatalities in the state. … It is important to note that our study was ecological and cross-sectional and could not determine cause-and-effect relationship,” the authors comment.

Over the four-year period of the study, the authors note there were 121,084 firearm fatalities and the average state-based firearm fatality rates varied from a high of 17.9 (Louisiana) to a low of 2.9 (Hawaii) per 100,000 individuals per year. Annual firearm legislative strength scores ranged from 0 (Utah) to 24 (Massachusetts) of 28 possible points, according to the results.

The states with the highest legislative strength scores (greater than or equal to 9) had a lower overall firearm fatality rate than those with the lowest scores (less than or equal to 2) for an absolute rate difference of 6.64 deaths per 100,000 individuals per year.

Compared with the states with the fewest laws, the states with the most laws had a lower firearm suicide rate (absolute rate difference 6.25 deaths per 100,000 individuals per year) and a lower firearm homicide rate (absolute rate difference 0.40 deaths per 100,000 individuals per year), according to the results.

“In conclusion, we found an association between the legislative strength of a state’s firearm laws – as measured by a higher number of laws – and a lower rate of firearm fatalities. The association was significant for firearm fatalities overall and for firearm suicide and firearm homicide deaths, individually. As our study could not determine a cause-and-effect relationship, further studies are necessary to define the nature of this association,” the study says.