Firearm Homicide Incidence, Within-state Firearm Laws, and Interstate Firearm Laws in US Counties

Universal Background Checks, Permit Requirements, and Firearm Homicide Rates

Importance

A loophole in US gun policy is that people can purchase guns from private sellers without going through any background check. Some states have addressed this loophole by requiring universal background checks for all gun sales, either at the point of sale or through a permit system; however, most studies on the effectiveness of universal background checks have not analyzed these 2 policy mechanisms separately.

Objective

To assess the association of point-of-sale background check law and gun permit law, separately, with firearm homicide rates from 1976 through 2022 using the same methods and model specification.

Design, Setting, and Participants

This cross-sectional study used a difference-in-differences, fixed-effects regression model to evaluate firearm laws and firearm homicide rates in 48 states from 1976 through 2022. Data were obtained for 48 states except New Hampshire and Vermont and were analyzed in January 2024.

Exposures

Implementation of either the law requiring a universal background check at point of sale for all firearms without a permit or the laws combining universal background checks and a state permit requirement for all gun purchasers.

Main Outcomes and Measures

Annual, state-specific rates of firearm homicide per 100 000 people.

Results

From 1976 through 2022, 12 states adopted the universal background check laws without permitting requirements and 7 states implemented gun permit laws covering all firearms. The mean (SD) firearm homicide rate was 4.3 (0.1) per 100 000 people. Universal background checks for all firearms alone (without a state permitting system) were not associated with overall homicide rates (percentage change, 1.3%; 95% CI, -6.9% to 10.4%) or firearm homicide rates (percentage change, 3.7%; 95% CI, -5.3% to 13.6%). A law requiring a permit for the purchase of all firearms was associated with significantly lower overall homicide rates (percentage change, -15.4%; 95% CI, -28.5% to -0.01%) and firearm homicide rates (percentage change, -18.3%; 95% CI, -32.0% to -1.9%).

Conclusions and Relevance

This cross-sectional study found that universal background checks alone were not associated with firearm homicide rates, but a permit requirement for the purchase and possession of firearms was associated with substantially reduced rates of firearm homicide. The findings suggest that combining universal background checks and permit-to-purchase requirements is an effective strategy for firearm-related fatality reduction.

Long gun violence in California versus Texas: How legislation can reduce firearm violence

Introduction

Long guns (LGs) are uniquely implicated in firearm violence and mass shootings. On 1/1/2019 California (CA) raised the minimum age to purchase LGs from 18 to 21. This study aimed to evaluate the incidence of LG violence in CA vs. Texas (TX), a state with rising firearm usage and fewer LG regulations, hypothesizing decreased LG firearm incidents in CA vs increased rates in TX after CA LG legislation.

Methods

A retrospective analysis of the Gun Violence Archive (2015-2021) was performed. An additional analysis of all firearm incidents within TX and CA was performed. CA and TX census data were used to calculate incidents of LG violence per 10,000,000 people. The primary outcome was the number of LG-related firearm incidents. Median yearly rates of LG violence per 10,000,000 people were compared for pre (2015-2018) vs post (2019-2021) CA LG legislation (Senate Bill 1100 (SB1100).

Results

Median LG incidents decreased in CA post-SB1100 (4.21 vs 1.52, p < 0.001) by nearly 64 %, whereas any gun firearm violence was similar pre vs post-SB1100 (77.0 vs 74.5 median incidents, p = 0.89). In contrast, median LG incidents increased after SB1100 (4.34 vs 5.17 median incidents, p = 0.011) by nearly 35 % in TX, with any gun incidents increasing by nearly 53 % (83.48 vs 127.46, p < 0.001).

Conclusion

CA LG firearm incidents decreased following SB 1100 legislation whereas the incidence in TX increased during this same time. Meanwhile, the incidence of any firearm violence remained similar in CA but increased in TX. This suggests the sharp decline in CA LG incidents may be related to SB1100. Accordingly, increasing the age to purchase a LG from 18 to 21 at a federal level may help curtail LG violence nationally.

Reporting and Description of Research Methodology in Studies Estimating Effects of Firearm Policies

BACKGROUND

Evidence about which firearm policies work, to what extent, and for whom is hotly debated, perhaps partly because variation in research methodology has produced mixed and inconclusive effect estimates. We conducted a scoping review of firearm policy research in the health sciences in the United States, focusing on methodological considerations for causal inference.

METHODS

We identified original, empirical articles indexed in PubMed from 1 January 2000 to 1 September 2021 that examined any of 18 prespecified firearm policies. We extracted key study components, including policy type(s) examined, policy operationalization, outcomes, study setting and population, study approach and design, causal language, and whether and how authors acknowledged potential sources of bias.

RESULTS

We screened 7733 articles and included 124. A plurality of studies used a legislative score as their primary exposure (n = 39; 32%) and did not examine change in policies over time (n = 47; 38%). Most examined firearm homicide (n = 51; 41%) or firearm suicide (n = 40; 32%) as outcomes. One-third adjusted for other firearm policies (n = 41; 33%). Three studies (2%) explicitly mentioned that their goal was to estimate causal effects, but over half used language implying causality (n = 72; 58%). Most acknowledged causal identification assumptions of temporality (n = 91; 73%) and exchangeability (n = 111; 90%); other assumptions were less often acknowledged. One-third of studies included bias analyses (n = 42; 34%).

CONCLUSIONS

We identified a range of methodologic approaches in firearm policy research in the health sciences. Acknowledging the imitations of data availability and quality, we identify opportunities to improve causal inferences about and reporting on the effects of firearm policies on population health.

Bullet holes: A novel model to identify the most impactful gaps in the firearm homicide prevention laws of each state

BACKGROUND

Firearm homicides (FH) are a major cause of mortality in the United States. Firearm law implementation is variable across states, and legislative gaps may represent opportunities for FH prevention. For each state, we sought to identify which firearm law category would have been most effective if implemented and how effective it would have been.

METHODS

We conducted a retrospective cohort study examining the effects of firearm laws on FH rates in the 48 contiguous US states 2010 to 2019. Data were obtained from the CDC WONDER and FBI UCR databases, State Firearm Law Database, and US Census. Firearm laws were grouped into 14 categories. We assessed the association between the presence of each law category and FH rate as an incidence rate ratio (IRR) using a Poisson regression accounting for state population characteristics and laws of surrounding states. We estimated the IRR for each state that did not have a given law category present and determined which of these missing law categories would have been associated with the greatest reduction in FH rate.

RESULTS

FH rates varied widely across states and increased from a mean of 3.2 (SD = 1.7) to 4.2 (SD = 2.9) FH per 100,000. All law categories were significantly associated with decreased FH rate ( p < 0.05), with IRR ranging from 0.25 to 0.85. The most effective missing law category differed between states but was most commonly child access prevention (34.09% of states), assault weapons and large-capacity magazines (15.91%), preemption (15.91%), and concealed carry permitting (13.64%). In total across 2010 to 2019, we estimated that 129,599 fewer FH would have occurred with enactment of the most effective missing law category in each state.

CONCLUSION

Modeling firearm law prevention of FH with regard to state legislative and population characteristics can identify the highest impact missing law categories in each state. These results can be used to inform efforts to reduce FH.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level IV.

Interstate Highway Connections and Traced Gun Transfers Between the 48 Contiguous United States

Importance

Interstate gun flow has critical implications for gun violence prevention, as gun transfers across state lines can undermine local gun control policies.

Objective

To identify possible gun trafficking routes along interstate highways in the US.

Design, Setting, and Participants

This repeated-measures, ecological, cross-sectional study used data from the Bureau of Alcohol, Tobacco, Firearms and Explosives from January 1, 2010, to December 31, 2019, to examine associations between interstate connections via 13 highways that each spanned at least 1000 miles and interstate traced gun transfer counts for the 48 contiguous United States. Analyses were completed in November 2023.

Exposures

Characteristics of the origin states and the transportation connections between the destination state and the origin states.

Main Outcomes and Measures

The main outcome was the total count of guns used in crimes in each destination state per year that were originally purchased in the origin state. Bayesian conditional autoregressive Poisson models were used to examine associations between the count of guns used in crime traced to interstate purchases and interstate highway connections between origin and destination states.

Results

Between 2010 and 2019, 526 801 guns used in crimes in the contiguous 48 states were traced to interstate purchases. Northbound gun transfers along the Interstate 95 corridor were greater than expected to New Jersey (incidence rate ratio [IRR], 2.80; 95% credible interval [CrI], 1.01-7.68) and Maryland (IRR, 3.07; 95% CrI, 1.09-8.61); transfers were similarly greater along Interstate 15 southbound, Interstate 25 southbound, Interstate 35 southbound, Interstate 75 northbound and southbound, Interstate 10 westbound, and Interstate 20 eastbound and westbound.

Conclusions and Relevance

This repeated-measures, ecological, cross-sectional study identified that guns used in crimes traced to interstate purchases moved routinely between states along multiple major transportation routes. Interstate gun transfers are a major contributor to gun crime, injury, and death in the US. National policies and interstate cooperation are needed to address this issue.

State-Level Firearm Laws and Firearm Homicide in US Cities: Heterogenous Associations by City Characteristics

Despite well-studied associations of state firearm laws with lower state- and county-level firearm homicide, there is a shortage of studies investigating differences in the effects of distinct state firearm law categories on various cities within the same state using identical methods. We examined associations of 5 categories of state firearm laws-pertaining to buyers, dealers, domestic violence, gun type/trafficking, and possession-with city-level firearm homicide, and then tested differential associations by city characteristics. City-level panel data on firearm homicide cases of 78 major cities from 2010 to 2020 was assessed from the Centers for Disease Control and Prevention's National Vital Statistics System. We modeled log-transformed firearm homicide rates as a function of firearm law scores, city, state, and year fixed effects, along with time-varying city-level confounders. We considered effect measure modification by poverty, unemployment, vacant housing, and income inequality. A one z-score increase in state gun type/trafficking, possession, and dealer law scores was associated with 25% (95% confidence interval [CI]:-0.37,-0.1), 19% (95% CI:-0.29,-0.07), and 17% (95% CI:-0.28, -0.4) lower firearm homicide rates, respectively. Protective associations were less pronounced in cities with high unemployment and high housing vacancy, but more pronounced in cities with high income inequality. In large US cities, state-level gun type/trafficking, possession, and dealer laws were associated with lower firearm homicide rates, but buyers and domestic violence laws were not. State firearm laws may have differential effects on firearm homicides based on city characteristics, and city-wide policies to enhance socioeconomic drivers may add benefits of firearm laws.

Investing in family-centered early childhood education: A conceptual model for preventing firearm homicide among Black male youth in the United States

INTRODUCTION

Firearms are now the number one killer of children and adolescents in the United States. Firearm homicides among Black male youth are the driver of this increase. Prevention requires a multi-faceted life course approach. Academic achievement has been identified as a protective factor. Early childhood education, which is linked to later achievement, is thus an intervention area of interest. Conceptualizing the potential links between early childhood education and reduced risk for youth firearm homicide is important for guiding policy advocacy and informing future research.

METHODS

This paper presents a conceptual model linking early childhood education to reduced risk for firearm homicide. Each link in the model is discussed, and a corresponding review of the literature is presented. The need for anti-racist policies to strengthen the impact of early childhood education is highlighted.

RESULTS

Early education and firearm homicide research are each well-established but largely disconnected. There are clear immediate benefits of early childhood education; however, these effects wane with time, particularly for youth of color. At the same time, juvenile delinquency-a major risk factor for firearm homicide-is influenced by educational inequities.

CONCLUSIONS

Effective interventions to reduce firearm homicides among Black male youth in the United States are needed. Early childhood education shows promise as an intervention. However, to have an impact, this education needs to be accessible and affordable for all, particularly families of color and low income. Societal structures and policies must also better support the positive gains seen through early childhood education to avoid dissipation.

Outcomes of selective non-operative management in adults with abdominal gunshot wounds: a systematic review and meta-analysis

BACKGROUND AND AIMS

Abdominal gunshot wounds (GSWs), a clinically devastating injury, can result in a variety of severe and lethal complications. Traditionally, exploratory laparotomy is the first-line approach for the management of abdominal GSWs, but it is associated with a considerable amount of unnecessary surgeries. At present, selective non-operative management (SNOM) of abdominal GSWs is becoming an effective and well-recognized approach, but it remains widely disputed since many surgeons are skeptical about the validity of SNOM in clinical practice. This meta-analysis aims to estimate the outcomes of SNOM and immediate laparotomy in patients with GSWs by collecting the currently available evidence.

METHODS

The PubMed , EMBASE , and Cochrane Library databases were searched. A random-effects model was employed. A pooled proportion with 95% confidence intervals (CIs) was calculated. Heterogeneity was evaluated using Cochran's Q test and I2 statistics.

RESULTS

Overall, 53 studies involving 60 291 participants were included. The pooled proportions of SNOM and SNOM failure were 27.0% (95% CI=24.0-30.0%) and 10.0% (95% CI=7.0-13.0%), respectively. The pooled mortality after SNOM and SNOM failure were 0.0% (95% CI=0.0-1.0%) and 0.0% (95% CI=0.0-0.0%), respectively. The pooled proportions of immediate laparotomy and unnecessary immediate laparotomy were 73.0% (95% CI=70.0-76.0%) and 10.0% (95% CI=8.0-13.0%), respectively. The pooled mortality after immediate laparotomy and unnecessary immediate laparotomy was 10.0% (95% CI=8.0-13.0%) and 0.0% (95% CI=0.0-1.0%), respectively. Heterogeneity was statistically significant in nearly all meta-analyses.

CONCLUSION

Immediate laparotomy is still the mainstay approach for the management of abdominal GSWs. Approximately one-third of patients with abdominal GSWs undergo SNOM. SNOM failure is not frequent, and its related mortality is also rare.

"We adjusted for race": now what? A systematic review of utilization and reporting of race in American Journal of Epidemiology and Epidemiology, 2020-2021

Race is a social construct, commonly used in epidemiologic research to adjust for confounding. However, adjustment of race may mask racial disparities, thereby perpetuating structural racism. We conducted a systematic review of articles published in Epidemiology and American Journal of Epidemiology between 2020 and 2021 to (1) understand how race, ethnicity, and similar social constructs were operationalized, used, and reported; and (2) characterize good and poor practices of utilization and reporting of race data on the basis of the extent to which they reveal or mask systemic racism. Original research articles were considered for full review and data extraction if race data were used in the study analysis. We extracted how race was categorized, used-as a descriptor, confounder, or for effect measure modification (EMM)-and reported if the authors discussed racial disparities and systemic bias-related mechanisms responsible for perpetuating the disparities. Of the 561 articles, 299 had race data available and 192 (34.2%) used race data in analyses. Among the 160 US-based studies, 81 different racial categorizations were used. Race was most often used as a confounder (52%), followed by effect measure modifier (33%), and descriptive variable (12%). Fewer than 1 in 4 articles (22.9%) exhibited good practices (EMM along with discussing disparities and mechanisms), 63.5% of the articles exhibited poor practices (confounding only or not discussing mechanisms), and 13.5% were considered neither poor nor good practices. We discuss implications and provide 13 recommendations for operationalization, utilization, and reporting of race in epidemiologic and public health research.

Association Between Markers of Structural Racism and Mass Shooting Events in Major US Cities

Importance

The root cause of mass shooting events (MSEs) and the populations most affected by them are poorly understood.

Objective

To examine the association between structural racism and mass shootings in major metropolitan cities in the United States.

Design, Setting, and Participants

This cross-sectional study of MSEs in the 51 largest metropolitan statistical areas (MSAs) in the United States analyzes population-based data from 2015 to 2019 and the Gun Violence Archive. The data analysis was performed from February 2021 to January 2022.

Exposure

Shooting event where 4 or more people not including the shooter were injured or killed.

Main Outcome and Measures

MSE incidence and markers of structural racism from demographic data, Gini income coefficient, Black-White segregation index, and violent crime rate.

Results

There were 865 MSEs across all 51 MSAs from 2015 to 2019 with a total of 3968 injuries and 828 fatalities. Higher segregation index (ρ = 0.46, P = .003) was associated with MSE incidence (adjusted per 100 000 population) using Spearman ρ analysis. Percentage of the MSA population comprising Black individuals (ρ = 0.76, P < .001), children in a single-parent household (ρ = 0.44, P < .001), and violent crime rate (ρ = 0.34, P = .03) were other variables associated with MSEs. On linear regression, structural racism, as measured by percentage of the MSA population comprising Black individuals, was associated with MSEs (β = 0.10; 95% CI, 0.05 to 0.14; P < .001). Segregation index (β = 0.02, 95% CI, -0.03 to 0.06; P = .53), children in a single-parent household (β = -0.04, 95% CI, -0.11 to 0.04; P = .28), and Gini income coefficient (β = -1.02; 95% CI, -11.97 to 9.93; P = .93) were not associated with MSEs on linear regression.

Conclusions and Relevance

This study found that major US cities with higher populations of Black individuals are more likely to be affected by MSEs, suggesting that structural racism may have a role in their incidence. Public health initiatives aiming to prevent MSEs should target factors associated with structural racism to address gun violence.

Gun shows and universal background check laws across state lines

States with more gun laws have fewer gun assaults, and associations are strongest for background check laws. However, sales between private buyers and sellers (i.e., gun shows) are exempt from some background check requirements according to federal and most state laws. The aim of this study was to determine whether gun shows are more likely to take place in counties that are near states with universal background check laws. This cross-sectional study used gun show data from a 2018 public online listing aggregated within 3107 counties in the contiguous 48 states. The main independent variable was the presence of a universal background check law in neighboring states. We controlled for potential drivers of demand for gun shows, including the total number of gun laws within-state and in neighboring states, local and in-flowing population size, and proportion of the local and in-flowing population who were gun owners. Bayesian conditional autoregressive Poisson models estimated associations between neighboring-state universal background check law and the presence of a gun show in each county while accounting for spatial dependencies and nesting of counties within states. Of the 1869 identified gun shows, nine of the states in which they occurred had a universal background check law. The presence of excess gun shows in counties near states with universal background check laws is consistent with the hypothesis that gun shows service demand from people seeking to circumvent prohibitions against gun purchases.

Association of State-Level Firearm-Related Deaths With Firearm Laws in Neighboring States

IMPORTANCE

Firearms are easily transported over state borders; hence permissive firearm laws in one state may have an interstate association with firearm-related deaths in nearby states.

OBJECTIVES

To examine whether certain firearm laws have an interstate association with firearm-related deaths in nearby states.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional observational study used data on state firearm-related deaths in the 48 contiguous states of the US between January 1, 2000, and December 31, 2019. A spatial autoregressive model with fixed effects for state and year was used to evaluate within-state, interstate, and overall associations between firearm laws and firearm-related deaths. Analyses were performed during January 2022.

EXPOSURES

The following 9 types of laws were evaluated: universal background checks for all firearms purchase, background checks for handgun sales at gun shows, license requirement to purchase all firearms, state dealer license requirement for handgun sales, requirement of retaining records of handgun sales, ban on purchasing a handgun on behalf of another, prohibition of firearm possession by persons who committed violent misdemeanors, required relinquishment of firearms for persons becoming prohibited from possessing them, and discretion in granting a concealed carry permit.

MAIN OUTCOMES AND MEASURES

State-level total firearm-related death rates, suicide rates, and homicide rates.

RESULTS

In sum, the study period included 662 883 firearm-related deaths of all intents. License requirement for firearm purchase had a within-state association (effect size, -1.79 [95% CI, -2.73 to -0.84]), interstate association (effect size, -10.60 [95% CI, -17.63 to -3.56]), and overall association (effect size, -12.38 [95% CI, -19.93 to -4.83]) per 100 000 population decrease in total firearm-related deaths. This law also had within-state association (effect size, -1.26 [95% CI, -1.72 to -0.80]), interstate association (effect size, -9.01 [95% CI, -15.00 to -3.02]), and overall association (effect size, -10.27 [95% CI, -16.53 to -4.01]) per 100 000 population decrease in firearm-related homicide.

CONCLUSIONS AND RELEVANCE

The findings of this pooled cross-sectional analysis suggest that certain firearm laws in one state were associated with other states' firearm-related deaths. Synergic legislative action in adjacent states, federal firearm legislation, and measures that reduce migration of firearms across state borders should be part of the overarching strategy to prevent firearm-related deaths.

A spatiotemporal model of firearm ownership in the United States

Firearm injury is a major public health crisis in the United States, where more than 200 people sustain a nonfatal firearm injury and more than 100 people die from it every day. To formulate policy that minimizes firearm-related harms, legislators must have access to spatially resolved firearm possession rates. Here, we create a spatiotemporal econometric model that estimates monthly state-level firearm ownership from two cogent proxies (background checks per capita and fraction of suicides committed with a firearm). From calibration on yearly survey data that assess ownership, we find that both proxies have predictive value in estimation of firearm ownership and that interactions between states cannot be neglected. We demonstrate use of the model in the study of relationships between media coverage, mass shootings, and firearm ownership, uncovering causal associations that are masked by the use of the proxies individually.

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A spatiotemporal model of firearm prevalence in the United States is created

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The econometric model predicts firearm ownership in every state for every month

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Information theory is used to detail causal links related to firearm prevalence

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The media can influence firearm prevalence, which in turn moderates mass shootings

Firearm violence is a major public health crisis in the United States, where more than 200 people sustain a nonfatal firearm injury and more than 100 people die from it every day. Despite these unsettling figures, scientific research on firearm-related harm significantly lags behind because spatially and temporally resolved data on firearm ownership are unavailable. This paper presents a spatiotemporal model that predicts firearm prevalence at the resolutions of one state and one month from the numbers of background checks and suicides committed with a firearm. Drawing on principles from econometrics, the model also accounts for interactions between states. The model’s output is challenged in causal analysis, which uncovers unprecedented associations between firearm prevalence, media output on firearm regulations, and mass shootings.

Exploring the complexity of firearm homicides in Harris County, Texas, from 2009 to 2021: Implications for theory and prevention

Firearm violence is a major health problem in the United States that clusters asymmetrically across geographic and demographic lines, and the persistence and unequal distribution of firearm violence suggests that novel causal explanations and theoretical frameworks may be warranted to guide preventive strategies. Thus, this study explores the following three hypotheses that are grounded in complex systems theory: 1) trends in firearm homicides risks have shifted heterogeneously in Harris County across endemic degree of risk; 2) firearm homicides clusters have remained resilient in Harris County across the study time period; and 3), the associations between known contextual correlates of firearm homicides and the distribution of firearm homicides risks in Harris County have manifested as nonlinear. Using a retrospective study design (n = 4,397) from January 1, 2009-June 31, 2021, medicolegal death investigation data from the Harris County Institute of Forensic Sciences and estimates of community characteristics from the American Community Survey were analyzed using Joinpoint trend analysis, kernel density geospatial analysis, and proportion tests. Trend analyses revealed that firearm homicides risks shifted heterogeneously across endemic degree of risk, with geographical areas with lower initial firearm homicides risks experiencing more profound upward shifts across the time period of the study. Geospatial analyses identified the resiliency of firearm homicides clusters across the study period, particularly in central, southern, and south-western districts of the city. Finally, the relationships between known contextual correlates and the distribution of firearm homicides risks in Harris County appeared to be nonlinear, particularly regarding ethnicity. This study provides data-driven results that suggest the plausibility of complex systems theory in advancing the understanding of causality in firearm homicides. Further, these findings support the urgent need for complex systems-informed preventive efforts that account for spatiotemporal heterogeneity, key interactions that generate nonlinearity, and latent feedback loops that underlie resiliency in firearm homicides.

A decade of hospital costs for firearm injuries in the United States by region, 2005-2015: government healthcare costs and firearm policies

Background

Firearm injuries are a costly, national public health emergency, and government-sponsored programs frequently pay these hospital costs. Understanding regional differences in firearm injury burden may be useful for crafting appropriate policies, especially with widely varying state gun laws.

Objective

To estimate the volume of, and hospital costs for, fatal and non-fatal firearm injuries from 2005 to 2015 for each region of the United States and analyze the proportionate cost by payer status.

Methods

We used the Healthcare Cost and Utilization Project Nationwide Inpatient Sample to identify patients admitted for firearm-related injuries from 2005 to 2015. We converted hospitalization charges to costs, which were inflation-adjusted to 2015 dollars. We used survey weights to create regional estimates. We used the Brady Gun Law to determine significance between firearm restrictiveness and firearm hospitalizations by region.

Results

There were a total of 317 479 firearm related admissions over the study period: 52 829 (16.66%), 66 671 (21.0%), 134 008 (42.2%), and 63 972 (20.2%) for the Northeast, Midwest, South, and West respectively, demonstrating high regional variability. In the Northeast, hospital costs were $1.98 billion (13.9% of total), of which 56.0% was covered by government payers; for the Midwest, costs were $1.53 billion (19.7% of total), 40.4% of which was covered by government payers; in the South costs were highest at $3.2 billion (41.4% of total), but government payers only covered 34.3%; and costs for the West were $1.94 billion (25.0% of total), with government programs covering 41.6% of the cost burden.

Conclusions

Hospital admissions and costs for firearm injuries demonstrated wide variation by region, suggesting opportunities for financial savings. As government insurance programs cover 41.5% of costs, tax dollars heavily subsidize the financial burden of firearm injuries and cost recovery options for treating residents injured by firearms should be considered. Injury control strategies have not been well applied to this national public health crisis.

Level of evidence

Level II, Economic and Value Based Evaluation

Firearm injury epidemiology in children and youth in Ontario, Canada: a population-based study

BACKGROUND AND OBJECTIVE

Despite firearms contributing to significant morbidity and mortality globally, firearm injury epidemiology is seldom described outside of the USA. We examined firearm injuries among youth in Canada, including weapon type, and intent.

DESIGN

Population-based, pooled cross-sectional study using linked health administrative and demographic databases.

SETTING

Ontario, Canada.

PARTICIPANTS

All children and youth from birth to 24 years, residing in Ontario from 1 April 2003 to 31 March 2018.

EXPOSURE

Firearm injury intent and weapon type using the International Classification of Disease-10 CM codes with Canadian enhancements. Secondary exposures were sociodemographics including age, sex, rurality and income.

MAIN OUTCOMES

Any hospital or death record of a firearm injury with counts and rates of firearm injuries described overall and stratified by weapon type and injury intent. Multivariable Poisson regression stratified by injury intent was used to calculate rate ratios of firearm injuries by weapon type.

RESULTS

Of 5486 children and youth with a firearm injury (annual rate: 8.8/100 000 population), 90.7% survived. Most injuries occurred in males (90.1%, 15.5/100 000 population). 62.3% (3416) of injuries were unintentional (5.5/100 000 population) of which 1.9% were deaths, whereas 26.5% (1452) were assault related (2.3/100 00 population) of which 18.7% were deaths. Self-injury accounted for 3.7% (204) of cases of which 72.0% were deaths. Across all intents, adjusted regression models showed males were at an increased risk of injury. Non-powdered firearms accounted for half (48.6%, 3.9/100 000 population) of all injuries. Compared with handguns, non-powdered firearms had a higher risk of causing unintentional injuries (adjusted rate ratio (aRR) 14.75, 95% CI 12.01 to 18.12) but not assault (aRR 0.84, 95% CI 0.70 to 1.00).

CONCLUSIONS

Firearm injuries are a preventable public health problem among youth in Ontario, Canada. Unintentional injuries and those caused by non-powdered firearms were most common and assault and self-injury contributed to substantial firearm-related deaths and should be a focus of prevention efforts.

Child Access Prevention Laws and Juvenile Firearm-Related Homicides

Debate over safe-storage gun regulations has captured public attention in the aftermath of several high-profile shootings committed by minors. To date, the existing literature provides no evidence that these laws are effective at deterring gun crime, a conclusion that has prompted the National Rifle Association to assert that such regulations are "unnecessary" and "ineffective." Using data from the FBI's Supplementary Homicide Reports for the period 1985-2013, we find that child access prevention (CAP) laws are associated with a 17 percent reduction in firearm-related homicides committed by juveniles. The estimated effect is stronger among whites than nonwhites and is driven by states enforcing the strictest safe-storage standard. We find no evidence that CAP laws are associated with firearm-related homicides committed by adults or with non-firearm-related homicides committed by juveniles, suggesting that the observed relationship between CAP laws and juvenile firearm-related homicides is causal.