A descriptive exploration of the geographic and sociodemographic concentration of firearm homicide in the United States, 2004-2018

Associations between gun violence exposure and suicide mortality rates in US counties

PURPOSE

Gun violence traumatizes communities and places a heavy burden on the mental health of those exposed. This ecological study examines the association between gun violence exposure and suicide mortality rates in US counties for the period 1999-2020 at various urbanicity levels.

METHODS

A Bayesian hierarchical Gamma-Poisson model with state random effects was employed to model the age-adjusted suicide mortality rates which adjusted for sex ratio, urbanicity, social vulnerability, gun ownership, culture of honor, and exposure spillovers from neighbouring counties.

RESULTS

Results indicate a small significant positive association between gun violence and suicide mortality rates. Urbanicity levels do not appear to modify this association, although the association may be slightly smaller for large urban metros.

CONCLUSIONS

Gun violence exposure may be positively associated with suicide mortality in US counties.

Modeling a needs assessment approach for policymakers to investigate, understand, and reduce gun violence

We conducted a needs assessment evaluation as part of a community effort to plan tailored responses to reduce gun violence in a midwestern town. Various data sources were used to analyze factors leading to gun violence. The results guided the creation of evidence-based response strategies. Study findings demonstrate that even in a small town, the nature and drivers of gun violence vary considerably at the micro level and thus should be examined at this level. In this paper, we present the recommendations that followed from our study, not as solutions for other jurisdictions to adopt on their face, but rather as an example of 1) the types of solutions that follow from a thorough analysis of a local problem, and 2) a plethora of potential responses by social institutions. The goal of the paper is to provide an example process for policymakers from jurisdictions of various sizes and locales of the application of a problem-oriented approach to understanding and preventing gun violence. Undertaking a comprehensive, micro-focus to analyze the gun violence problem and its drivers in a jurisdiction provides essential information to guide the formulation of tailored, evidence-based responses.

Association between social vulnerability factors and homicide and suicide rates - United States, 2016 - 2020

BACKGROUND

Differences in social and environmental factors contribute to disparities in fatal injury rates. This study assessed the relationship between social vulnerability and homicide and suicide rates across United States counties.

METHODS

County-level age-adjusted homicide and suicide rates for 2016-2020 were linked with data from the Centers for Disease Control and Prevention's 2020 Social Vulnerability Index (SVI), a dataset identifying socially vulnerable communities. We conducted negative binomial regressions to examine the association between SVI and homicide and suicide rates, overall and by Census region/division. We mapped county-level data for SVI and homicide and suicide rates in bivariate choropleth maps.

RESULTS

Overall SVI was associated with homicide rates across U.S. counties. While no association was found for overall SVI and suicide rates, Socioeconomic Status and Racial & Ethnic Minority Status domains were associated. The geographic distribution of SVI and homicide and suicide rates varied spatially; notably, counties in the South had the greatest levels of social vulnerability and greatest homicide rates.

CONCLUSIONS

Our findings demonstrate county-level social vulnerability is associated with homicide rates but may be more nuanced for suicide rates. A modified SVI for injury should include additional social and structural determinants and exclude variables not applicable to injuries.

PRACTICAL APPLICATIONS

This study combines the SVI with homicide and suicide data, enabling researchers to examine related social and environmental factors. Modifying the SVI to include relevant predictors could improve injury prevention strategies by prioritizing efforts in areas with high social vulnerability.

An introduction to bayesian spatial smoothing methods for disease mapping: modeling county firearm suicide mortality rates

This article introduces bayesian spatial smoothing models for disease mapping-a specific application of small area estimation where the full universe of data is known-to a wider audience of public health professionals using firearm suicide as a motivating example. Besag, York, and Mollié (BYM) Poisson spatial and space-time smoothing models were fitted to firearm suicide counts for the years 2014-2018. County raw death rates in 2018 ranged from 0 to 24.81 deaths per 10 000 people. However, the highest mortality rate was highly unstable, based on only 2 deaths in a population of approximately 800, and 80.5% of contiguous US counties experienced fewer than 10 firearm suicide deaths and were thus suppressed. Spatially smoothed county firearm suicide mortality estimates ranged from 0.06 to 4.05 deaths per 10 000 people and could be reported for all counties. The space-time smoothing model produced similar estimates with narrower credible intervals as it allowed counties to gain precision from adjacent neighbors and their own counts in adjacent years. bayesian spatial smoothing methods are a useful tool for evaluating spatial health disparities in small geographies where small numbers can result in highly variable rate estimates, and new estimation techniques in R software have made fitting these models more accessible to researchers.

Pooled Analysis of Trauma Centers Better Predicts Risk Factors for Firearm Violence Reinjury

INTRODUCTION

Many trauma centers use the first firearm injury admission as a reachable moment to mitigate reinjury. Understanding repeat firearm violence can be difficult in metropolitan areas with multiple trauma centers and laws that prohibit sharing private health information across health systems. We hypothesized that risk factors for repeat firearm violence could be better understood using pooled data from two major metropolitan trauma centers.

METHODS

Two level I trauma center registries were queried (2007-2017) for firearm injury admissions using International Classification of Diseases, Ninth and Tenth Revision (ICD9/10) Ecodes. A pseudo encryption tool allowed sharing of deidentified firearm injury and repeat firearm injury data without disclosing private health information. Factors associated with firearm reinjury admissions including, age, sex, race, payor, injury severity, intent, and discharge, were assessed by multivariable logistic regression.

RESULTS

We identified 2145 patients with firearm injury admissions, 89 of whom had a subsequent repeat firearm injury admission. Majority of repeat firearm admissions were assaulted (91%), male (97.8%), and non-Hispanic Black (86.5%). 31.5% of repeat firearm injury admissions were admitted to a different trauma center from their initial admission. Independent predictors of repeat firearm injuries were age (adjusted odds ratio [aOR] 0.94, P < 0.001), male sex (aOR 6.18, P = 0.013), non-Hispanic Black race (aOR 5.14, P = 0.007), or discharge against medical advice (aOR 6.64, P=<0.001).

CONCLUSIONS

Nearly a third of repeat firearm injury admissions would have been missed in the current study without pooled metropolitan trauma center data. The incidence of repeat firearm violence is increasing and those at the highest risk for reinjury need to be targeted for mitigating interventions.

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.

Trauma Demographics and Injury Prevention

Traumatic injury is a leading cause of death in the United States. Risk of traumatic injury varies by sex, age, geography, and race/ethnicity. Understanding the nuances of risk for a particular population is essential in designing, implementing, and evaluating injury prevention initiatives.

National community disparities in prehospital penetrating trauma adjusted for income, 2020-2021

INTRODUCTION

While Black individuals experienced disproportionately increased firearm violence and deaths during the COVID-19 pandemic, less is known about community level disparities. We sought to evaluate national community race and ethnicity differences in 2020 and 2021 rates of penetrating trauma.

METHODS

We linked the 2018-2021 National Emergency Medical Services Information System databases to ZIP Code demographics. We stratified encounters into majority race/ethnicity communities (>50% White, Black, or Hispanic/Latino). We used logistic regression to compare penetrating trauma for each community in 2020 and 2021 to a combined 2018-2019 historical baseline. Majority Black and majority Hispanic/Latino communities were compared to majority White communities for each year. Analyses were adjusted for household income.

RESULTS

We included 87,504,097 encounters (259,449 penetrating traumas). All communities had increased odds of trauma in 2020 when compared to 2018-2019, but this increase was largest for Black communities (aOR 1.4, [1.3-1.4]; White communities - aOR 1.2, [1.2-1.3]; Hispanic/Latino communities - aOR 1.1. [1.1-1.2]). There was a similar trend of increased penetrating trauma in 2021 for Black (aOR 1.2, [1.2-1.3]); White (aOR 1.2, [1.1-1.2]); Hispanic/Latino (aOR 1.1, [1.1-1.1]). Comparing penetrating trauma in each year to White communities, Black communities had higher odds of trauma in all years (2018/2019 - aOR 3.0, [3.0-3.1]; 2020 - aOR 3.3, [3.3-3.4]; 2021 - aOR 3.3, [3.2-3.2]). Hispanic/Latino also had more trauma each year but to a lesser degree (2018/2019 - aOR 2.0, [2.0-2.0]; 2020 - aOR 1.8, [1.8-1.9]; 2021 - aOR 1.9, [1.8-1.9]).

CONCLUSION

Black communities were most impacted by increased penetrating trauma rates in 2020 and 2021 even after adjusting for income.

Costs of Fatal and Nonfatal Firearm Injuries in the U.S., 2019 and 2020

INTRODUCTION

Firearm-related injuries are among the five leading causes of death for people aged 1-44 years in the U.S. The immediate and long-term harms of firearm injuries pose an economic burden on society. Fatal and nonfatal firearm injury costs in the U.S. were estimated providing up-to-date economic burden estimates.

METHODS

Counts of nonfatal firearm injuries were obtained from the 2019-2020 Healthcare Cost and Utilization Project Nationwide Emergency Department Sample. Data on nonfatal injury intent were obtained from the National Electronic Injury Surveillance System - Firearm Injury Surveillance System. Counts of deaths (firearm as underlying cause) were obtained from the 2019-2020 multiple cause-of-death mortality data from the National Vital Statistics System. Analyses were conducted in 2023.

RESULTS

The total cost of firearm related injuries and deaths in the U.S. for 2020 was $493.2 billion, a 16 percent increase compared with 2019. There are significant disparities in the cost of firearm deaths in 2019-2020, with non-Hispanic Black people, males, and young and middle-aged groups being the most affected.

CONCLUSIONS

Most of the nonfatal firearm injury-related costs are attributed to hospitalization. These findings highlight the racial/ethnic differences in fatal firearm injuries and the disproportionate cost burden to urban areas. Addressing this important public health problem can help ameliorate the costs to our society from the rising rates of firearm injuries.

Incidence of and Factors Associated With Recurrent Firearm Injury Among Patients Presenting to St. Louis Trauma Centers, 2010 to 2019 : A Cohort Study

BACKGROUND

Firearm injuries are a public health crisis in the United States.

OBJECTIVE

To examine the incidence and factors associated with recurrent firearm injuries and death among patients presenting with an acute (index), nonfatal firearm injury.

DESIGN

Multicenter, observational, cohort study.

SETTING

Four adult and pediatric level I trauma hospitals in St. Louis, Missouri, 2010 to 2019.

PARTICIPANTS

Consecutive adult and pediatric patients (n = 9553) presenting to a participating hospital with a nonfatal acute firearm injury.

MEASUREMENTS

Data on firearm-injured patient demographics, hospital and diagnostic information, health insurance status, and death were collected from the St. Louis Region-Wide Hospital-Based Violence Intervention Program Data Repository. The Centers for Disease Control and Prevention (CDC) Social Vulnerability Index was used to characterize the social vulnerability of the census tracts of patients' residences. Analysis included descriptive statistics and time-to-event analyses estimating the probability of experiencing a recurrent firearm injury.

RESULTS

We identified 10 293 acutely firearm-injured patients of whom 9553 survived the injury and comprised the analytic sample. Over a median follow-up of 3.5 years (IQR, 1.5 to 6.4 years), 1155 patients experienced a recurrent firearm injury including 5 firearm suicides and 149 fatal firearm injuries. Persons experiencing recurrent firearm injury were young (25.3 ± 9.5 years), predominantly male (93%), Black (96%), and uninsured (50%), and resided in high social vulnerability regions (65%). The estimated risk for firearm reinjury was 7% at 1 year and 17% at 8 years.

LIMITATIONS

Limited data on comorbidities and patient-level social determinants of health. Inability to account for recurrent injuries presenting to nonstudy hospitals.

CONCLUSION

Recurrent injury and death are frequent among survivors of firearm injury, particularly among patients from socially vulnerable areas. Our findings highlight the need for interventions to prevent recurrence.

PRIMARY FUNDING SOURCE

Emergency Medicine Foundation-AFFIRM and Missouri Foundation for Health.

Association between social vulnerability factors and unintentional fatal injury rates - United States, 2015-2019

BACKGROUND

Differences in social and environmental factors can contribute to disparities in fatal injury rates. The purpose of this study was to examine the relationship between social and environmental factors and unintentional fatal injury across counties in the United States and how this relationship varies by geography.

METHODS

County-level vital statistics on age-adjusted unintentional fatal injury rates for 2015-2019 were linked with county-level data from the 2018 Social Vulnerability Index (SVI), a dataset identifying socially vulnerable communities. We conducted linear regression to examine the association between SVI and unintentional fatal injury, overall and by Census region/division. We mapped county-level data for SVI and unintentional fatal injury rates in bivariate choropleth maps using quartiles.

RESULTS

SVI was positively associated with unintentional fatal injury (β = 18.29, p < 0.001) across U.S. counties. The geographic distribution of SVI and unintentional fatal injury rates varied spatially and substantially for U.S. counties, with counties in the South and West regions having the greatest levels of SVI and rates of unintentional fatal injury.

CONCLUSIONS

Our findings demonstrate that the social vulnerability of counties is associated with unintentional fatal injury rates. Modification of the SVI for injury research could include additional social determinants and exclude variables not applicable to injuries. A modified SVI could inform unintentional injury prevention strategies by prioritizing efforts in areas with high levels of social vulnerability.

PRACTICAL APPLICATIONS

This study is the first step in combining the SVI and injury mortality data to provide researchers with an index to investigate upstream factors related to injury.

Fatal and non-fatal firearm-related injuries in Canada, 2016-2020: a population-based study using three administrative databases

BACKGROUND

Firearms are a substantial cause of injury-related morbidity and mortality in Canada and globally, though evidence from contexts other than the USA is relatively limited. We examined deaths, hospitalizations and emergency department (ED) visits due to firearm-related injuries in Canada to identify population groups at increased risk of fatal and non-fatal outcomes.

METHODS

We conducted a population-based study using three national administrative databases on deaths, hospitalizations, and ED visits. ICD-10 codes were used to identify firearm-related injuries from January 1, 2016, through December 31, 2020. Fatal and non-fatal firearm injuries were classified as suicide/self-harm, homicide/assault, unintentional, undetermined or legal intervention injuries. We analyzed the data with counts, rates and proportions, stratified by sex, age group, province/territory, and year.

RESULTS

Over the 5-year period, we identified 4005 deaths, 3169 hospitalizations, and 2847 ED visits related to firearm injuries in various jurisdictions in Canada. Males comprised the majority of fatal and non-fatal injury cases. The highest rates of fatal and non-fatal firearm injuries were among 20- to 34-year-olds. The leading cause of fatal firearm injuries was self-harm (72.3%). For non-fatal firearm hospitalizations and ED visits, assault (48.8%) and unintentional injuries (62.8%) were the leading causes of injury. Rates varied by province and territory.

CONCLUSIONS

Our results showed that males comprised the majority of fatal and non-fatal firearm injuries in Canada. The rates of both fatal and non-fatal firearm injuries were highest among the 20- to 34-year-old age group. This comprehensive overview of the epidemiology of firearm injuries in Canada provides baseline data for ongoing surveillance and policy evaluation related to public health interventions.

Geospatial analysis of firearm injuries in an urban setting: Individual rather than community characteristics affect firearm injury risk

BACKGROUND

The relationship between individual/socioeconomic characteristics and firearm injury risk in an urban center was evaluated.

METHODS

A hospital registry was used to identify individuals in Baltimore City who experienced interpersonal firearm injury in 2019 (FA). Injuries that did not satisfy this criterion were used as a comparison group (NF). Socioeconomic characteristics were linked to home address at the block group level. Regression analysis was used to determine predictors of firearm injury. Clusters of high and low firearm relative to non-firearm injuries were identified.

RESULTS

A total of 1293 individuals were included (FA = 277, NF = 1016). The FA group lived in communities with lower income (p = 0.005), higher poverty (p = 0.007), and more Black residents (p < 0.001). Individual level factors were stronger predictors of firearm injury than community factors on multivariate regression with Black race associated with 5x higher odds of firearm injury (p < 0.001). Firearm injury clustered in areas of low socioeconomic status.

CONCLUSIONS

Individual versus community factors have a greater influence on firearm injury risk. Prevention efforts should target young, Black men in urban centers.

Child Access Prevention Laws and Non-Hispanic Black Youth Firearm Mortality

Firearm injuries are the leading cause of death for youths 19 and younger in general and the third leading cause of death for non-Hispanic Black youths. Child Access Prevention (CAP) laws have been explored concerning their impact on firearm mortality reduction among heterogenous groups of youth, but not specifically among non-Hispanic Black youths. We analyzed data related to non-Hispanic Black youth firearm mortality, non-Hispanic Black poverty rates, firearm dealer density, and CAP laws for each state to ascertain the impact of CAP laws from 2015 to 2019. During the study period, a total of 6778 non-Hispanic Black youths died due to firearm trauma with the leading causes of death being homicides (85.8%); mostly seen among males (96%), and in the South (53.2%). When compared by CAP laws, the states with the strongest laws had statistically significantly lower rates of firearm mortality than states with the weakest laws. After adjusting for state poverty and firearm dealer density, the differences were not statistically significant but still, stronger CAP laws were associated with lower rates of firearm mortality among non-Hispanic Black youth. CAP laws alone can have a modest impact on non-Hispanic Black youth firearm mortality. To adequately reduce firearm mortality among non-Hispanic Black youths, the state and local governments should, along with CAP laws, enact policies to reduce poverty, crime, access to firearms by criminals, and neighborhood dysfunction among non-Hispanic Black communities.

County-Level Social Vulnerability and Emergency Department Visits for Firearm Injuries - 10 U.S. Jurisdictions, January 1, 2018-December 31, 2021

At least 100,000 persons in the United States experience a fatal or nonfatal firearm injury each year.* CDC examined rates of firearm injury emergency department (ED) visits by community social vulnerability using data from CDC's Firearm Injury Surveillance Through Emergency Rooms (FASTER) program.^† ED visit data, shared with CDC's National Syndromic Surveillance Program (NSSP)^§ during 2018-2021, were analyzed for 647 counties in 10 FASTER-funded jurisdictions.^¶ County-level social vulnerability data were obtained from the 2018 Social Vulnerability Index (SVI).** Rates of ED visits for firearm injuries (number of firearm injury ED visits per 100,000 ED visits) were calculated across tertile levels of social vulnerability. Negative binomial regression models were used to estimate rate ratios (RRs) and associated 95% CIs comparing rates of ED visits across social vulnerability levels. During 2018-2021, compared with rates in counties with low overall social vulnerability, the firearm injury ED visit rate was 1.34 times as high in counties with medium social vulnerability and 1.80 times as high in counties with high social vulnerability. Similar patterns were observed for the SVI themes of socioeconomic status and housing type and transportation, but not for the themes of household composition and disability status or racial and ethnic minority status and language proficiency. More timely data^†† on firearm injury ED visits by social vulnerability can help identify communities disproportionately experiencing elevated firearm injury rates. States and communities can use the best available evidence to implement comprehensive prevention strategies that address inequities in the social and structural conditions that contribute to risk for violence, including creating protective community environments, strengthening economic supports, and intervening to reduce harms and prevent future risk (e.g., with hospital-based violence intervention programs) (1,2).

Vital Signs: Changes in Firearm Homicide and Suicide Rates - United States, 2019-2020

INTRODUCTION

The majority of homicides (79%) and suicides (53%) in the United States involved a firearm in 2020. High firearm homicide and suicide rates and corresponding inequities by race and ethnicity and poverty level represent important public health concerns. This study examined changes in firearm homicide and firearm suicide rates coinciding with the emergence of the COVID-19 pandemic in 2020.

METHODS

National vital statistics and population data were integrated with urbanization and poverty measures at the county level. Population-based firearm homicide and suicide rates were examined by age, sex, race and ethnicity, geographic area, level of urbanization, and level of poverty.

RESULTS

From 2019 to 2020, the overall firearm homicide rate increased 34.6%, from 4.6 to 6.1 per 100,000 persons. The largest increases occurred among non-Hispanic Black or African American males aged 10-44 years and non-Hispanic American Indian or Alaska Native (AI/AN) males aged 25-44 years. Rates of firearm homicide were lowest and increased least at the lowest poverty level and were higher and showed larger increases at higher poverty levels. The overall firearm suicide rate remained relatively unchanged from 2019 to 2020 (7.9 to 8.1); however, in some populations, including AI/AN males aged 10-44 years, rates did increase.

CONCLUSIONS AND IMPLICATIONS FOR PUBLIC HEALTH PRACTICE

During the COVID-19 pandemic, the firearm homicide rate in the United States reached its highest level since 1994, with substantial increases among several population subgroups. These increases have widened disparities in rates by race and ethnicity and poverty level. Several increases in firearm suicide rates were also observed. Implementation of comprehensive strategies employing proven approaches that address underlying economic, physical, and social conditions contributing to the risks for violence and suicide is urgently needed to reduce these rates and disparities.