Importance Over 30 000 people die annually in the United States from injuries caused by firearms. Although most firearm laws are enacted by states, whether the laws are associated with rates of firearm deaths is uncertain.
Objective To evaluate whether more firearm laws in a state are associated with fewer firearm fatalities.
Design Using an ecological and cross-sectional method, we retrospectively analyzed all firearm-related deaths reported to the Centers for Disease Control and Prevention Web-based Injury Statistics Query and Reporting System from 2007 through 2010. We used state-level firearm legislation across 5 categories of laws to create a “legislative strength score,” and measured the association of the score with state mortality rates using a clustered Poisson regression. States were divided into quartiles based on their score.
Setting Fifty US states.
Participants Populations of all US states.
Main Outcome Measures The outcome measures were state-level firearm-related fatalities per 100 000 individuals per year overall, for suicide, and for homicide. In various models, we controlled for age, sex, race/ethnicity, poverty, unemployment, college education, population density, nonfirearm violence–related deaths, and household firearm ownership.
Results Over the 4-year study period, there were 121 084 firearm fatalities. 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. States in the highest quartile of legislative strength (scores of ≥9) had a lower overall firearm fatality rate than those in the lowest quartile (scores of ≤2) (absolute rate difference, 6.64 deaths/100 000/y; age-adjusted incident rate ratio [IRR], 0.58; 95% CI, 0.37-0.92). Compared with the quartile of states with the fewest laws, the quartile with the most laws had a lower firearm suicide rate (absolute rate difference, 6.25 deaths/100 000/y; IRR, 0.63; 95% CI, 0.48-0.83) and a lower firearm homicide rate (absolute rate difference, 0.40 deaths/100 000/y; IRR, 0.60; 95% CI, 0.38-0.95).
Conclusions and Relevance A higher number of firearm laws in a state are associated with a lower rate of firearm fatalities in the state, overall and for suicides and homicides individually. As our study could not determine cause-and-effect relationships, further studies are necessary to define the nature of this association.
The total number of annual firearm fatalities in the United States has been stable over the last decade.1,2 From 2007 to 2010, the range was 31 224 to 31 672 fatalities per year.1 There is substantial variation in firearm fatality rates among states, however, with the average annual state-based firearm fatality rates ranging from a high of 17.9 (Louisiana) to a low of 2.9 (Hawaii) per 100 000 individuals during these years. In 2010, firearms killed 68% of the 16 259 victims of homicide. In the same year, there were 38 364 suicides, of which 51% were by firearms.1 Beyond the loss of life and nonfatal traumatic injuries, the financial cost of firearm injuries is enormous. In 2005, the medical costs associated with fatal and nonfatal firearm injuries were estimated at $112 million and $599 million, respectively, and work loss costs were estimated at $40.5 billion.1
Mass killings such as those in Columbine and Aurora in Colorado, the Wisconsin Sikh temple shooting, and most recently the Newtown, Connecticut, school massacre have renewed debate about the need for more stringent firearm legislation. Some have called for more restrictions on gun purchases.3 Others have called for arming teachers.4 It is challenging to calculate the exact number of firearm laws: a single law may have multiple parts; laws are potentially passed at the national, state, county, and city level; and there is no repository available for tallying these laws.5 The factoid that there are “20 000 laws governing firearms”5 has been erroneously quoted since 1965, but the most recent and reliable estimate, performed in 1999, counted about 300 state firearm laws.6
The real question is not about the number of firearm laws but whether the laws ultimately safeguard the citizens they are intended to protect. Although multiple studies have examined the relationship between federal and state firearm laws and homicide and suicide rates, the overall association between firearm legislation and firearm mortality is uncertain and remains controversial.7,8
We evaluated whether variations in the strength of state firearm legislation are associated with variations in the rates of firearm fatalities. We examined overall firearm death rates as well as firearm suicide and firearm homicide rates by state, controlling for other factors previously associated with firearm fatalities.