Does the declining lethality of gunshot injuries mask a rising epidemic of gun violence in the United States?

Situational and Victim Correlates of Increased Case Fatality Rates in Los Angeles Shootings, 2005-2021

The gun assault case fatality rate measures the fraction of shooting victims who die from their wounds. Considerable debate has surrounded whether gun assault case fatality rates have changed over time and what factors may be involved. We use crime event data from Los Angeles to examine the victim and situational correlates of gun assault case fatality rates over time. We estimated log binomial regression models for the probability of death in each year from 2005 to 2021, conditioned on situational and victim characteristics of the crime. Case fatality rates increased by around 1.3% per year between 2005 and 2021 from around 15.9 to 19.7%. Baseline case fatality rates differed systematically by most situational and victim but followed similar temporal trends. Only victim age significantly covaried with the temporal trend in case fatality rates. An individual shot in Los Angeles in 2021 was 23.7% more likely to die than the equivalent victim in 2005. The steady increase in case fatality rates suggests that there were around 394 excess fatalities over what would have occurred if case fatality rates remained at the 2005 level. Increases in the average age of victims over time may contribute to the general temporal trend. We hypothesize that older victims are more likely to be shot indoors where lethal close-range wounds are more likely.

Costs for Long-Term Health Care After a Police Shooting in Ontario, Canada

Importance

Police shootings can cause serious acute injury, and knowledge of subsequent health outcomes may inform interventions to improve care.

Objective

To analyze long-term health care costs among survivors of police shootings compared with those surviving nonfirearm police enforcement injuries using a retrospective design.

Design, Setting, and Participants

This population-based cohort analysis identified adults (age ≥16 years) who were injured by police and required emergency medical care between April 1, 2002, and March 31, 2022, in Ontario, Canada.

Exposure

Police shootings compared with other mechanisms of injury involving police.

Main Outcomes and Measures

Long-term health care costs determined using a validated costing algorithm. Secondary outcomes included short-term mortality, acute care treatments, and rates of subsequent disability.

Results

Over the study, 13 545 adults were injured from police enforcement (mean [SD] age, 35 [12] years; 11 637 males [86%]). A total of 13 520 individuals survived acute injury, and 8755 had long-term financial data available (88 surviving firearm injury, 8667 surviving nonfirearm injury). Patients surviving firearm injury had 3 times greater health care costs per year (CAD$16 223 vs CAD$5412; mean increase, CAD$9967; 95% CI, 6697-13 237; US $11 982 vs US $3997; mean increase, US $7361; 95% CI, 4946-9776; P < .001). Greater costs after a firearm injury were not explained by baseline costs and primarily reflected increased psychiatric care. Other characteristics associated with increased long-term health care costs included prior mental illness and a substance use diagnosis.

Conclusions and Relevance

In this longitudinal cohort study of long-term health care costs, patients surviving a police shooting had substantial health care costs compared with those injured from other forms of police enforcement. Costs primarily reflected psychiatric care and suggest the need to prioritize early recognition and prevention.

Injury-Transplantation Interval-Dependent Amelioration of Axonal Degeneration and Motor Deficit in Rats with Penetrating Traumatic Brain Injury

Penetrating traumatic brain injury (pTBI) is increasingly survivable, but permanently disabling as adult mammalian nervous system does not regenerate. Recently, our group demonstrated transplant location-dependent neuroprotection and safety of clinical trial-grade human neural stem cell (hNSC) transplantation in a rodent model of acute pTBI. To evaluate whether longer injury-transplantation intervals marked by chronic inflammation impede engraftment, 60 male Sprague-Dawley rats were randomized to three sets. Each set was divided equally into two groups: 1) with no injury (sham) or 2) pTBI. After either 1 week (groups 1 and 2), 2 weeks (groups 3 and 4), or 4 weeks after injury (groups 5 and 6), each animal received 0.5 million hNSCs perilesionally. A seventh group of pTBI animals treated with vehicle served as the negative control. All animals were allowed to survive 12 weeks with standard chemical immunosuppression. Motor capacity was assessed pre-transplant to establish injury-induced deficit and followed by testing at 8 and 12 weeks after transplantation. Animals were euthanized, perfused, and examined for lesion size, axonal degeneration, and engraftment. Compared to vehicle, transplanted groups showed a trend for reduced lesion size and axonal injury across intervals. Remote secondary axonal injury was significantly reduced in groups 2 and 4, but not in group 6. The majority of animals showed robust engraftment independent of the injury-transplant time interval. Modest amelioration of motor deficit paralleled the axonal injury trend. In aggregate, pTBI-induced remote secondary axonal injury was resolved by early, but not delayed, hNSC transplantation.

Suicide versus homicide firearm injury patterns on trauma systems in a study of the National Trauma Data Bank (NTDB)

Firearm related mortality in the USA surpassed all other developed countries. This study hypothesizes that injury patterns, weapon type, and mortality differ between suicide groups as opposed to homicide. The American College of Surgeons National Trauma Database was queried from January 2017 to December 2019. All firearm related injuries were included, and weapon type was abstracted. Differences between homicide and suicide groups by sex, age, race, and injury severity were compared using a Mann–Whitney test for numerical data and Fisher’s exact test for categorical data. The association between weapon type and mortality relative to suicide as opposed to homicide was assessed in Fisher’s exact tests. Significance was defined as p < 0.05. There were 100,031 homicide and 11,714 suicide subjects that met inclusion criteria. Homicides were mostly assault victims (97.6%), male (88%), African–American (62%), had less severe injury (mean (ISS) 12.07) and a median age of 20 years old (IQR: 14, 30, p < 0.01). Suicides were mostly male (83%), white (79%), had more severe injury (mean ISS 20.73), and a median age of 36 years old (IQR: 19, 54, p < 0.01). Suicide group had higher odds of head/neck (OR = 13.6) or face (OR = 5.7) injuries, with lower odds of injury to chest (OR = 0.55), abdominal or pelvic contents (OR = 0.25), extremities or pelvic girdle (OR = 0.15), or superficial soft tissue (OR = 0.32). Mortality rate was higher for suicide group (44.8%; 95% confidence interval (CI) 43.9%, 45.7%) compared to the homicide group (11.5%; 95% CI 11.3%, 11.7%). Suicide had higher mortality, more severe injuries, and more head/neck/facial injuries than homicide. Majority of suicides were with handguns.

Assessing fetal human neural stem cells tumorigenicity potential in athymic rats with penetrating traumatic brain injury (pTBI)

Traumatic brain injuries (TBI) often produce disability in survivors due to unresolved inflammation and progressive neurodegeneration. The central nervous system in mammals is incapable of self-repair. Two decades of preclinical studies and clinical trials have provided insights into TBI pathophysiology that could be utilized to develop clinically relevant therapy. Our laboratory recently reported efficacy of clinical trial grade fetal human neural stem cells (hNSCs) in immunosuppressed rats with penetrating traumatic brain injury (pTBI). Next, in compliance with the United States Food and Drug Administration (USFDA) guidance, this study explores safety by assessing the tumorigenicity potential of intracranial hNSC transplants in athymic rats with pTBI. First, the maximum tolerated dose (MTD) was determined. Then, forty athymic pTBI rats were randomized to either: Group A. pTBI + vehicle or Group B. pTBI + hNSCs at MTD one week after injury with 6-months survival, sufficient time to uncover transplant associated tumorigenicity. A board-certified Pathologist examined hematoxylin-eosin (H&E), Ki67 immunostained brain and spinal cord, serial sections along with several abnormal peripheral masses for evidence of lesion, transplant, and oncogenesis. There was no evidence of transplant derived tumors or oncogenic tissue necrosis. Consistent with athymic literature, the lesion remained unchanged even after robust hNSC engraftment. This safety study supports the conclusion that hNSCs are safe for transplantation in pTBI. The differences in lesion expansion between immunosuppressed and athymic rats in the presence of hNSCs suggests an unexpected role for thymus derived cells in resolution of trauma induced inflammation.

Public guns, private violence: The association of city-level firearm availability and intimate partner homicide in the United States

This city-level study examines the association of federally licensed firearm dealers (FFLs) and measures of illegal firearm availability with the risk of intimate partner homicide. Annual data for a sample of 286 large cities in the United States were collected for the years 2010-2019, incorporating city-level information on the number of gun-perpetrated homicides, the rate of licensed firearm dealers, and guns reported lost or stolen. All data were compiled and analyzed in 2020. Negative binomial models were used to assess the relation of firearm availability and gun homicide by intimate partners, in comparison to gun homicide between non-intimates. Results indicate that a higher rate of licensed firearm dealers was associated with a higher risk of intimate partner homicide, although more pronounced in states with lower-than-average existing gun ownership. This association was robust to different analytical methods and alternate ways of capturing illegal guns. A supplementary analysis using unique data from The Trace further supports the argument that FFL presence is a risk factor for intimate partner firearm homicide specifically, but not necessarily firearm homicide characterized by other motives.

Non-fatal gun violence and community health behaviors: A neighborhood analysis in Philadelphia

Research shows that community violence is associated with an array of negative health outcomes, yet no study has examined the specific association between different types of gun violence and collective health behaviors in local neighborhoods. Using data from neighborhoods in the city of Philadelphia, this study examines the association between total, fatal, and non-fatal gun violence and measures of physical inactivity, obesity, sleep, and smoking. We find the rate of non-fatal shootings is associated with a composite measure of health behaviors, net of all neighborhood-level covariates and general community violence. Ancillary analyses show that non-fatal shootings are particularly associated with physical inactivity and obesity. Notably, fatal shootings are not associated with any behavioral health measure after accounting for nonlethal shootings. The results support improved data collection efforts to measure non-fatal shootings across the U.S. and greater attention to the collective health consequences of gun violence in local communities.

Trends in Firearm Injury and Motor Vehicle Crash Case Fatality by Age Group, 2003-2013

Importance

If changes over time in trauma care apply to both firearm injuries and motor vehicle crashes (MVCs) similarly, differences in mechanism-specific case-fatality trends may suggest changes over time in injury severity.

Objectives

To analyze national trends in case-fatality percentages at levels I and II trauma centers for injuries due to MVC, firearm assault, self-inflicted firearm injury, and unintentional firearm injury by age and to analyze trends in injury severity scores (ISSs) and the percentage of out-of-hospital deaths by mechanism.

Design, Setting, and Participants

From November 15, 2017, to July 4, 2018, repeated cross-sectional measures analysis of 1 335 044 patients treated at level I or II trauma centers from January 1, 2003, through December 31, 2013, was conducted using 2 data sources: the National Trauma Data Bank National Sample Program, with survey weights to estimate annual median ISS, total injuries and total deaths at levels I and II trauma centers, and the Centers for Disease Control and Prevention's Wide-Ranging Online Data for Epidemiologic Research for percentages of out-of-hospital deaths.

Main Outcome Measures

The main outcome was annual case-fatality percentage (total died/total injured), calculated by mechanism across 3 age groups (15-34 years, 35-54 years, and ≥55 years) and 5 categories of ISS (1-15 [mild] 16-24, 25-40, 41-66, and 67-75 [severe]). Linear regression was performed to estimate annual trends in case-fatality percentage by mechanism, age group, and ISS. Annual trends in percentages of out-of-hospital deaths and median ISSs by mechanism were estimated. Sensitivity analyses included the Durbin-Watson statistic for autocorrelation and Prais-Winsten regression models.

Results

Among 1 335 044 patients treated at level I or II trauma centers, self-inflicted firearm injury had a case-fatality percentage of 42.8%, and assault with a firearm had a case-fatality percentage of 11.1%, the 2 highest of the injuries studied. The injury case-fatality percentage was lower each year for MVCs but did not change for any firearm intent overall or for any age group. Overall, median ISS increased annually for firearm suicide (0.31; 95% CI, 0.00-0.61). The annual percentage of out-of-hospital deaths was lower each year for MVCs (-0.24; 95% CI, -0.43 to -0.05) but not for any firearm intents. In sensitivity analyses, the annual percentage of out-of-hospital deaths for MVCs no longer showed a decline.

Conclusions and Relevance

Stagnant case-fatality percentages for firearm injuries juxtaposed to improvements for MVCs across age-groups and ISS categories suggests worsening severity of firearm injuries over the study period.

Firearm assault in Philadelphia, 2005-2014: a comparison of police and trauma registry data

Background

Firearm injury is a major public health burden in the USA. Absent a single, reliable data source, researchers have attempted to describe firearm injury epidemiology using trauma registry data. To understand the implications of this approach, we compared trends in firearm assault incidence and case-fatality in Philadelphia over 10 years from two sources: the Pennsylvania Trauma Outcomes Study (PTOS), Pennsylvania’s state-mandated trauma registry, and the Philadelphia Police Department database (PPD) of firearm assaults.

Methods

We included PTOS firearm assault patients treated in Philadelphia County and PPD database firearm assault victims from 2005 to 2014. We calculated counts of fatal and non-fatal incidents using PTOS and PPD data. We used generalized linear models adjusted for seasonality to estimate temporal trends in firearm assault rates and case-fatality for both data sources and compared patient demographics and injury characteristics between the two.

Results

A total of 6988 PTOS and 14 172 PPD subjects met the inclusion criteria. In both data sets, firearm assault rates decreased significantly during the study period (PTOS: 5.19 vs. 3.43 per 10 000 person-years, change/year: −0.21, 95% CI −0.26 to –0.16; PPD: 10.97 vs. 6.70 per 10 000 person-years, change/year: −0.53, 95% CI −0.62 to –0.44). PTOS mean case-fatality rate was 26.5% and decreased significantly (change/year: −0.41, 95% CI −0.78% to 0.04%). PPD mean case-fatality rate was 18.9% with no significant change over time (p=0.41).

Discussion

Relative to PPD data, PTOS data underestimated firearm assault incidence and overestimated mortality. Trends in case-fatality rates were disparate across the two data sources. A true understanding of firearm injury in the USA requires comprehensive data collection on the incidence, nature, and severity of these injuries. As trauma registry data are by definition incomplete, combining data sources is essential. Local law enforcement data are an important potential source for studying city-level firearm injury.

Level of evidence

Level III, epidemiological.

Constant Lethality of Gunshot Injuries From Firearm Assault: United States, 2003-2012

OBJECTIVES

To investigate the validity of the apparent downward trend in the national case-fatality rate for gunshot wounds from assault.

METHODS

We reanalyzed the estimated annual number of nonfatal firearm injuries the National Electronic Injury Surveillance System reported from 2003 to 2012. We adjusted the estimates for discontinuities created by the substitution of 1 hospital for another in the sample and for a downward trend in the percentage of gunshot injuries classified as "unknown circumstance." Firearm homicide data are from the Centers for Disease Control and Prevention, Web-based Injury Statistics Query and Reporting System.

RESULTS

The unadjusted National Electronic Injury Surveillance System estimate increased by 49%, yielding a decline in the case-fatality rate from 25% to 18%. Our adjustments eliminated these trends; the case-fatality rate was 22% in both 2003 and 2012.

CONCLUSIONS

With reasonable adjustments, the trend in nonfatal injuries from interpersonal firearms assault tracks the flat trend in firearms homicides, suggesting that there was no increase in firearms violence during this period. The case-fatality rate did not change, and trauma care improvements did not influence the firearms homicide trend.

Amelioration of Penetrating Ballistic-Like Brain Injury Induced Cognitive Deficits after Neuronal Differentiation of Transplanted Human Neural Stem Cells

Penetrating traumatic brain injury (PTBI) is one of the major cause of death and disability worldwide. Previous studies with penetrating ballistic-like brain injury (PBBI), a PTBI rat model revealed widespread perilesional neurodegeneration, similar to that seen in humans following gunshot wound to the head, which is unmitigated by any available therapies to date. Therefore, we evaluated human neural stem cell (hNSC) engraftment to putatively exploit the potential of cell therapy that has been seen in other central nervous system injury models. Toward this objective, green fluorescent protein (GFP) labeled hNSC (400,000 per animal) were transplanted in immunosuppressed Sprague-Dawley (SD), Fisher, and athymic (ATN) PBBI rats 1 week after injury. Tacrolimus (3 mg/kg 2 days prior to transplantation, then 1 mg/kg/day), methylprednisolone (10 mg/kg on the day of transplant, 1 mg/kg/week thereafter), and mycophenolate mofetil (30 mg/kg/day) for 7 days following transplantation were used to confer immunosuppression. Engraftment in SD and ATN was comparable at 8 weeks post-transplantation. Evaluation of hNSC differentiation and distribution revealed increased neuronal differentiation of transplanted cells with time. At 16 weeks post-transplantation, neither cell proliferation nor glial lineage markers were detected. Transplanted cell morphology was similar to that of neighboring host neurons, and there was relatively little migration of cells from the peritransplant site. By 16 weeks, GFP-positive processes extended both rostrocaudally and bilaterally into parenchyma, spreading along host white matter tracts, traversing the internal capsule, and extending ∼13 mm caudally from transplantation site reaching into the brainstem. In a Morris water maze test at 8 weeks post-transplantation, animals with transplants had shorter latency to platform than vehicle-treated animals. However, weak injury-induced cognitive deficits in the control group at the delayed time point confounded benefits of durable engraftment and neuronal differentiation. Therefore, these results justify further studies to progress towards clinical translation of hNSC therapy for PTBI.

Spatio-temporal patterns of gun violence in Syracuse, New York 2009-2015

Gun violence in the United States of America is a large public health problem that disproportionately affects urban areas. The epidemiology of gun violence reflects various aspects of an infectious disease including spatial and temporal clustering. We examined the spatial and temporal trends of gun violence in Syracuse, New York, a city of 145,000. We used a spatial scan statistic to reveal spatio-temporal clusters of gunshots investigated and corroborated by Syracuse City Police Department for the years 2009-2015. We also examined predictors of areas with increased gun violence using a multi-level zero-inflated Poisson regression with data from the 2010 census. Two space-time clusters of gun violence were revealed in the city. Higher rates of segregation, poverty and the summer months were all associated with increased risk of gun violence. Previous gunshots in the area were associated with a 26.8% increase in the risk of gun violence. Gun violence in Syracuse, NY is both spatially and temporally stable, with some neighborhoods of the city greatly afflicted.

Geo-demographics of gunshot wound injuries in Miami-Dade county, 2002-2012

Background

We evaluated correlates of gunshot wound (GSW) injuries in Miami-Dade County, Florida. Firearm-related injury has previously been linked to socio- and geo-demographic indicators such as occupation, income, neighborhood and race in other metropolitan areas, but remains understudied in Miami.

Methods

We reviewed 4,547 cases from a Level I trauma center’s patient registry involving an intentional firearm-related injury occurring from 2002 to 2012. During this eleven-year study period, this trauma center was the only one in Miami-Dade County, and thus representative of countywide injuries.

Results

The crude morbidity rate of GSW injury over the 11-year period was 15 per 100,000 persons with a crude mortality rate of 0.27 per 100,000 persons. The case fatality rate of injured patients was 15.4%. Both morbidity and mortality increased modestly over the 11-year study period. The total number of GSW patients rose annually during the study period and patients were disproportionately young, black males, though we observed higher severity of injury in white populations. Geo-demographic analysis revealed that both GSW incident locations and patient home addresses are spatially clustered in predominantly poor, black neighborhoods near downtown Miami, and that these patterns persisted throughout the study period. Using spatial regression, we observed that census tract-level GSW incidence rates (coded by home address) were associated with a census tract’s proportion of black residents (P < .001), single-parent households (P < .001), and median age (P < .001) (R² = .42).

Conclusions

These findings represent the first representative geo-demographic analysis of GSW injuries in Miami-Dade County, and offer evidence to support urgent, targeted community engagement and prevention strategies to reduce local firearm violence.

Predictors and Outcomes of Pediatric Firearm Injuries Treated in the Emergency Department: Differences by Mechanism of Intent

OBJECTIVE

Firearm injuries among children are a major clinical and public health concern and one of the leading causes of pediatric fatalities. Our objective was to investigate differences in predictors and clinical outcomes between self-inflicted, violent, and unintentional pediatric firearm injuries for patients who present to pediatric emergency departments (EDs).

METHODS

We conducted a retrospective study of patients 0 to 21 years old treated in 37 pediatric academic EDs from 2004 to 2014. Patients were classified into the injury intent categories of self-inflicted, violent, and unintentional firearm injury using the International Classification of Diseases, 9th edition, Clinical Modification (ICD-9-CM) diagnoses and external causes of injury codes. Multivariable multinomial regression models compared groups.

RESULTS

We identified 9,628 firearm injuries from 2004 to 2014: 109 (1%) self-inflicted, 2,394 (25%) violent, and 7,125 (74%) unintentional. Male sex, increasing age, nonwhite race, public insurance, residing in an urban zip code, and lower zip code-level median household income were all independently associated with violent firearm injuries, relative to self-inflicted and unintentional injuries. Self-inflicted injuries were at the highest risk for hospital admission, death, intensive care unit services, surgical services, and increased length of stay, followed by violent injuries with intermediate risk and unintentional injuries at the lowest risk

CONCLUSIONS

Self-inflicted, violent, and unintentional firearm injuries in children had distinct demographic risk factors and clinical and utilization outcomes. Targeted prevention and intervention efforts should be developed to reduce the incidence and severity of these injuries.

Racial Disparities in Cranial Gunshot Wounds: Intent and Survival

BACKGROUND

Gunshot wounds (GSW) to the head are associated with the highest mortality of all gun-related injuries, with assault reported as the leading cause of penetrating GSW. Several studies have explored factors and trends related to assault and self-inflicted GSW separately. The aim of this study was to investigate epidemiological characteristics and racial differences collectively in patients with GSW to the head by examining associations to injury intent and survival.

METHOD

A retrospective study was performed by accessing the hospital trauma registry at our regional Level 1 Trauma Center. A query of neurosurgery consults with penetrating trauma was completed from January 2008 to October 2013. Patients with penetrating intracranial GSW were included in the study. A chi-square test was used to evaluate association between patients' characteristics and intent of injury. Logistic regression analyses predicting intent of injury and survival were also conducted.

RESULTS

Of 111 patients, the majority were male (87.4 %). Most were African American (57.7 %) and Caucasian (35.1 %). Compared to African Americans, Caucasian patients were more likely to inflict self-harm (odds ratio (OR) 16.369 (95 % confidence interval (CI) 5.633-47.571), p < 0.0001), while African Americans (OR 26.413 (95 % CI 8.957-77.890), p < 0.0001) were more likely to be victims of assault. Race and other demographic variables did not predict survival nor did intent of injury (p = 0.368).

CONCLUSION

This study reports that there are racial disparities between assault GSW and self-inflicted GSW. However, neither race nor intent is a predictor of survival outcome. Targeted efforts are needed to reduce occurrence of cranial GSW events in order to decrease associated morbidity and mortality.

Long-term mortality of patients surviving firearm violence

OBJECTIVE

We aim to calculate the 5-year mortality after surviving to hospital discharge after a firearm injury and estimate the association of firearm injury with later mortality.

METHODS

We performed a retrospective cohort study of patients from an urban emergency department (ED) and trauma centre in Oakland, California, USA, in 2007. We created three cohorts of patients presenting for (1) gunshot wound (GSW), (2) MVC and (3) assault without a firearm. Demographic and clinical information was obtained from the clinical chart, and the California Department of Public Health Vital Statistics and Social Security Death Master File (2007-2012) were queried to identify patients who died.

RESULTS

We analysed 516 GSW patients, 992 MVC patients and 695 non-GSW assault patients. Of the GSW patients, 86.4% were alive at 5 years. All-cause 5-year mortality among GSW victims surviving to discharge after injury was 5.1%. Compared with MVC patients, both GSW and non-GSW assault patients have higher risk of death at 5 years (HR 2.54 (95% CI 1.41 to 4.59) and HR 1.64 (95% CI 1.01 to 2.68), respectively), adjusting for age, sex and race. Risk of death was higher in the first year for the GSW cohort (HR 6.14 (95% CI 2.35 to 16.08) and HR 5.06 (95% CI 1.88 to 13.63) as compared with MVC and non-GSW assault cohorts, respectively). Homicide was the cause of death in 79.2% of GSW patients who died after surviving the index injury.

CONCLUSION

Among individuals presenting to the ED after injury or assault and surviving to discharge, firearm injury exposure is an important predictor of death within 5 years and most pronounced in the first year after injury.

Firearm Prevalence and Homicides of Law Enforcement Officers in the United States

OBJECTIVES

In the United States, state firearm ownership has been correlated with homicide rates. More than 90% of homicides of law enforcement officers (LEOs) are committed with firearms. We examined the relationship between state firearm ownership rates and LEO occupational homicide rates.

METHODS

We obtained the number LEOs killed from 1996 to 2010 from a Federal Bureau of Investigation (FBI) database. We calculated homicide rates per state as the number of officers killed per number of LEOs per state, obtained from another FBI database. We obtained the mean household firearm ownership for each state from the Behavioral Risk Factor Surveillance System.

RESULTS

Using Poisson regression and controlling for factors known to affect homicide rates, we associated firearm ownership with the homicide rates for LEOs (incidence rate ratio = 1.044; P = .005); our results were supported by cross-sectional and longitudinal sensitivity analyses. LEO homicide rates were 3 times higher in states with high firearm ownership compared with states with low firearm ownership.

CONCLUSIONS

High public gun ownership is a risk for occupational mortality for LEOs in the United States. States could consider methods for reducing firearm ownership as a way to reduce occupational deaths of LEOs.