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.

Prolonged hourly neurological examinations are associated with increased delirium and no discernible benefit in mild/moderate geriatric traumatic brain injury.

BACKGROUND: Serial neurological examinations (NEs) are routinely recommended in the intensive care unit (ICU) within the first 24 hours following a traumatic brain injury (TBI). There are currently no widely accepted guidelines for the frequency of NEs. Disruptions to the sleep-wake cycles increase the delirium rate. We aimed to evaluate whether there is a correlation between prolonged hourly (Q1)-NE and development of delirium and to determine if this practice reduces the likelihood of missing the detection of a process requiring emergent intervention. METHODS: A retrospective analysis of patients with mild/moderate TBI, admitted to the ICU with serial NEs, was performed. Cohorts were stratified by the duration of exposure to Q1-NE, into prolonged (≥24 hours) and nonprolonged (<24 hours). Our primary outcomes of interest were delirium, evaluated using the Confusion Assessment Method; radiological progression from baseline images; neurological deterioration (focal neurological deficit, abnormal pupillary examination, or Glasgow Coma Scale score decrease >2); and neurosurgical procedures. RESULTS: A total of 522 patients were included. No significant differences were found in demographics. Patients in the prolonged Q1-NE group (26.1%) had higher Injury Severity Score with similar head Abbreviated Injury Score, significantly higher delirium rate (59% vs. 35%, p < 0.001), and a longer hospital/ICU length of stay when compared with the nonprolonged Q1-NE group. No neurosurgical interventions were found to be performed emergently as a result of findings on NEs. Multivariate analysis demonstrated that prolonged Q1-NE was the only independent risk factor associated with a 2.5-fold increase in delirium rate. The number needed to harm for prolonged Q1-NE was 4. CONCLUSION: Geriatric patients with mild/moderate TBI exposed to Q1-NE for periods longer than 24 hours had nearly a threefold increase in ICU delirium rate. One of five patients exposed to prolonged Q1-NE is harmed by the development of delirium. No patients were found to directly benefit as a result of more frequent NEs. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level IV.

Distinct roles for LTalpha3 and LTalpha1beta2 produced by B cells contribute to their multi-faceted impact on ileitis.

B lymphocytes may facilitate chronic inflammation through antibody production or secretion of cytokines, including lymphotoxin (LT)-a1b2 associated with development of lymphoid tissue. Tertiary lymphoid structures (TLS) characterize human and murine ileitis by suppressing outflow from the ileum. Here, we show that B cell-derived secretory IgA protected against ileal inflammation, whereas B cell-derived LTa guarded against ileitis-associated loss of body mass. We initially hypothesized this protection resulted from formation of TLS that suppressed lymphatic outflow and thereby restrained systemic spread of inflammatory signals, but B cell-selective deletion of LTb did not exacerbate weight loss, despite eliminating TLS. Instead, weight loss driven by the cachectic cytokine TNF was exacerbated when LTa3, another ligand for TNF receptors, was selectively neutralized. Thus, B cells' multi-faceted impact on ileitis includes generating secretory IgA, expressing LTa1b2 to drive formation of TLS, and producing LTa3 for protecting against weight loss in the presence of TNF.

State-Level Analysis of Intimate Partner Violence, Abortion Access, and Peripartum Homicide: Call for Screening and Violence Interventions for Pregnant Patients.

BACKGROUND: Despite representing 4% of the global population, the US has the fifth highest number of intentional homicides in the world. Peripartum people represent a unique and vulnerable subset of homicide victims. This study aimed to understand the risk factors for peripartum homicide. STUDY DESIGN: We used data from the 2018 to 2020 National Violent Death Reporting System to compare homicide rates of peripartum and nonperipartum people capable of becoming pregnant (12 to 50 years of age). Peripartum was defined as currently pregnant or within 1-year postpartum. We additionally compared state-level peripartum homicide rates between states categorized as restrictive, neutral, or protective of abortion. Pearson's chi-square and Wilcoxon rank-sum tests were used. RESULTS: There were 496 peripartum compared with 8,644 nonperipartum homicide victims. The peripartum group was younger (27.4 ± 71 vs 33.0 ± 9.6, p < 0.001). Intimate partner violence causing the homicide was more common in the peripartum group (39.9% vs 26.4%, p < 0.001). Firearms were used in 63.4% of homicides among the peripartum group compared with 49.5% in the comparison (p < 0.001). A significant difference was observed in peripartum homicide between states based on policies regarding abortion access (protective 0.37, neutral 0.45, restrictive 0.64; p < 0.01); the same trend was not seen with male homicides. CONCLUSIONS: Compared with nonperipartum peers, peripartum people are at increased risk for homicide due to intimate partner violence, specifically due to firearm violence. Increasing rates of peripartum homicide occur in states with policies that are restrictive to abortion access. There is a dire need for universal screening and interventions for peripartum patients. Research and policies to reduce violence against pregnant people must also consider the important role that abortion access plays in protecting safety.

Ludwig's Angina: Higher Incidence and Worse Outcomes Associated With the Onset of the Coronavirus Disease 2019 Pandemic.

Background: Ludwig's angina (LA) is a diffuse cellulitis of the submandibular space and adjacent tissues. During the coronavirus disease 2019 (COVID-19) pandemic, odontogenic treatments were often delayed because of the implementation of safety measures to avoid the spread of the virus. We hypothesized that delayed odontogenic treatments associated with the onset of the COVID-19 pandemic would be associated with an increase in the incidence of LA and worse outcomes related to these infections. Patients and Methods: Patients from June 2018 to June 2022 with computed tomography images suggestive of LA and confirmed by ear, nose, throat (ENT) consult were included. We abstracted demographics, outcomes, clinical management, and microbiology. Patients were stratified into pre-COVID and COVID-onset. Our primary outcome, incidence of LA, was defined as: (new LA cases) ÷ (ED evaluations of oral or dental infections × 1.5 years). Results: In the pre-COVID group, we identified 32 of 1,301 patients with LA for an incidence of 0.02 per year. The COVID-onset group consisted of 41 of 641 patients, with an incidence of 0.04 per year. In the COVID-onset group, progression to necrotizing fasciitis was more likely (0% vs. 15%; p < 0.024), and they returned to the operating room for repeated debridement (3% vs. 22%; p < 0.020). Likewise, hospital length of stay, intensive care unit (ICU) length of stay, and ventilator days were higher (4.3 ± 3.5 vs. 9.5 ± 11.3; 1.1 ± 1.2 vs. 9.5 ± 7.1; 0.3 ± 1 vs. 3.6 ± 7.1; p < 0.001). Conclusions: Although the prognosis for dental infections diagnosed early is generally favorable, we observed a notable increase in the incidence of LA after the onset of the COVID-19 pandemic. Moreover, complications stemming from these infections became more severe in the COVID-onset era. Specifically, the likelihood of necrotizing fasciitis showed a substantial increase, accompanied by an increased risk of respiratory failure and mediastinitis.

Defects in vein valve PROX1/FOXC2 antithrombotic pathway in endothelial cells drive the hypercoagulable state induced by trauma and critical illness.

OBJECTIVES: Deep venous thrombosis (DVT) causes significant morbidity and mortality after trauma. Recently, we have shown that blood flow patterns at vein valves induce oscillatory stress genes, which maintain an anticoagulant endothelial phenotype that inhibits spontaneous clotting at vein valves and sinuses, is lost in the presence of DVT in human pathological samples, and is dependent on expression of the transcription factor FOXC2. We describe an assay, modifying our mouse multiple injury system, which shows evidence of clinically relevant microthrombosis and hypercoagulability applicable to the study of spontaneous DVT in trauma without requiring direct vascular injury or ligation. Finally, we investigated whether these model findings are relevant to a human model of critical illness by examining gene expression changes by quantitative polymerase chain reaction and immunofluorescence in veins collected from critically ill. METHODS: C57/Bl6 mice were subjected to a modified mouse multiple injury model with liver crush injury, crush and pseudofracture of a single lower extremity, and 15% total blood volume hemorrhage. Serum was assayed for d-dimer at 2, 6, 24, and 48 hours after injury by enzyme-linked immunosorbent assay. For the thrombin clotting assay, veins of the leg were exposed, 100 µL of 1 mM rhodamine (6 g) was injected retro-orbitally, and 450 µg/mL thrombin was then applied to the surface of the vein with examination of real-time clot formation via in vivo immunofluorescence microscopy. Images were then examined for percentage area of clot coverage of visible mouse saphenous and common femoral vein. Vein valve specific knockout of FOXC2 was induced with tamoxifen treatment in PROX1 Ert2Cre FOXC2 fl/fl mice as previously described. Animals were then subjected to a modified mouse multiple injury model with liver crush injury, crush and pseudofracture of a single lower extremity, and 15% total blood volume hemorrhage. Twenty-four hours after injury, we examined the valve phenotype in naive versus multiple injury animals, with and without loss of the FOXC2 gene from the vein valve (FOXC2 del ) via the thrombin assay. Images were then examined for proximity of clot formation to the valve present at the junction of the mouse saphenous, tibial, and superficial femoral vein and presence of spontaneous microthrombi present in the veins before exposure to thrombin. Human vein samples were obtained from excess tissue preserved after harvest for elective cardiac surgery and from organ donors after organ procurement. Sections were submitted for paraffin embedding and then assayed by immunofluorescence for PROX1, FOXC2, thrombomodulin, endothelial protein C receptor, and von Willebrand's factor. All animal studies were reviewed and approved by the Institutional Animal Care and Use Committee, and all human studies reviewed and approved by the institutional review board. RESULTS: After mouse multiple injuries, enzyme-linked immunosorbent assay for d-dimer showed evidence of products of fibrin breakdown consistent with formation of clot related to injury, fibrinolysis, and/or microthrombosis. The thrombin clotting assay demonstrated higher percentage area of vein covered with clot when exposed to thrombin in the multiple injury animals compared with uninjured (45% vs. 27% p = 0.0002) consistent with a phenotype of hypercoagulable state after trauma in our model system. Unmanipulated FoxC2 knockout mice manifest increased clotting at the vein valve as compared with unmanipulated wild type animals. After multiple injuries, wild type mice manifest increase clotting at the vein after thrombin exposure ( p = 0.0033), and equivalent to that of valvular knockout of FoxC2 (FoxC2del), recapitulating the phenotype seen in FoxC2 knockout animals. The combination of multiple injuries and FoxC2 knockout resulted in spontaneous microthrombi in 50% of the animals, a phenotype not observed with either multiple injuries or FoxC2 deficiency alone (χ 2 , p = 0.017). Finally, human vein samples demonstrated the protective vein valve phenotype of increased FOXC2 and PROX1 and showed decreased expression in the critically ill organ donor population by immunofluorescence imaging in organ donor samples. CONCLUSION: We have established a novel model of posttrauma hypercoagulation that does not require direct restriction of venous flow or direct injury to the vessel endothelium to assay for hypercoagulability and can generate spontaneous microthrombosis when combined with valve-specific FOXC2 knockout. We find that multiple injuries induce a procoagulant phenotype that recapitulates the valvular hypercoagulability seen in FOXC2 knockout and, in critically ill human specimens, find evidence for loss of oscillatory shear stress-induced gene expression of FOXC2 and PROX1 in the valvular endothelium consistent with potential loss of DVT-protective valvular phenotype.

Trauma of abortion restrictions and forced pregnancy: urgent implications for acute care surgeons.

In the aftermath of the Supreme Court's Dobbs vs. Jackson Women's Health decision, acute care surgeons face an increased likelihood of seeing patients with complications from both self-managed abortions and forced pregnancy in underserved areas of reproductive and maternity care throughout the USA. Acute care surgeons have an ethical and legal duty to provide care to these patients, especially in obstetrics and gynecology deserts, which already exist in much of the country and are likely to be exacerbated by legislation banning abortion. Structural inequities lead to an over-representation of poor individuals and people of color among patients seeking abortion care, and it is imperative to make central the fact that people of color who can become pregnant will be disproportionately affected by this legislation in every respect. Acute care surgeons must take action to become aware of and trained to treat both the direct clinical complications and the extragestational consequences of reproductive injustice, while also using their collective voices to reaffirm the right to abortion as essential healthcare in the USA.

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.

Dysregulation of the leukocyte signaling landscape during acute COVID-19.

The global COVID-19 pandemic has claimed the lives of more than 750,000 US citizens. Dysregulation of the immune system underlies the pathogenesis of COVID-19, with inflammation mediated tissue injury to the lung in the setting of suppressed systemic immune function. To define the molecular mechanisms of immune dysfunction in COVID-19 we utilized a systems immunology approach centered on the circulating leukocyte phosphoproteome measured by mass cytometry. We find that although COVID-19 is associated with wholesale activation of a broad set of signaling pathways across myeloid and lymphoid cell populations, STAT3 phosphorylation predominated in both monocytes and T cells. STAT3 phosphorylation was tightly correlated with circulating IL-6 levels and high levels of phospho-STAT3 was associated with decreased markers of myeloid cell maturation/activation and decreased ex-vivo T cell IFN-γ production, demonstrating that during COVID-19 dysregulated cellular activation is associated with suppression of immune effector cell function. Collectively, these data reconcile the systemic inflammatory response and functional immunosuppression induced by COVID-19 and suggest STAT3 signaling may be the central pathophysiologic mechanism driving immune dysfunction in COVID-19.

When REBOA grows wings: Resuscitative endovascular balloon occlusion of the aorta to facilitate aeromedical transport.

BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a helpful adjunct in the control of non-compressible truncal hemorrhage. Concerns regarding ischemia time limits its applicability in transfer. We describe the first reported case of civilian transfer via aeromedical transport to a higher level of care with a zone 3 REBOA catheter deployed. CASE REPORT: We present the case of a patient in hemorrhagic shock with a complex pelvic fracture exceeding the capability of a rural level-two trauma center requiring the use of REBOA catheter to permit aeromedical transport to a level-one trauma center for definitive embolization. CONCLUSION: Deployment of REBOA catheter to facilitate aeromedical transport to an appropriate level of care may be considered if travel times can be kept brief and there is a process and training in place to empower flight medics to consider transporting with a REBOA deployed.

IL-7 Immunotherapy in a Nonimmunocompromised Patient With Intractable Fungal Wound Sepsis.

A nonimmunocompromised patient developed life-threatening soft tissue infection with Trichosporon asahii, Fusarium, and Saksenaea that progressed despite maximum antifungal therapies and aggressive debridement. Interleukin-7 immunotherapy resulted in clinical improvement, fungal clearance, reversal of lymphopenia, and improved T-cell function. Immunoadjuvant therapies to boost host immunity may be efficacious in life-threatening fungal infections.

Extrathoracic multiple trauma dysregulates neutrophil function and exacerbates pneumonia-induced lung injury.

BACKGROUND: Forty percent of critically ill trauma patients will develop an infectious complication. Pneumonia is the most common cause of death of trauma patients surviving their initial insult. We previously demonstrated that polytrauma (PT), defined as two or more severe injuries in at least two areas of the body, induces emergency hematopoiesis characterized by accelerated myelopoiesis in the bone marrow and increased myeloid cell frequency in the peripheral tissues. We hypothesized that PT alone induces priming of neutrophils, resulting in hyperactivation upon secondary exposure to bacteria and causing acute lung injury and increased susceptibility to secondary exposure to Pseudomonas aeruginosa pneumonia. METHODS: C57BL/6 mice were subjected to PT consisting of a lower extremity pseudofracture, liver crush injury, and 15% blood-volume hemorrhage. Pneumonia was induced by intratracheal injection of 5 × 106 CFU live P. aeruginosa or 1 × 107 of heat-killed P. aeruginosa (HKPA). For reactive oxygen species (ROS), studies polymorphonuclear neutrophils (PMNs) were isolated by immunomagnetic bead negative selection and stimulated ex-vivo with HKPA. Reactive oxygen species production was measured by immunofluorescence. For histology, lung sections were stained by hematoxylin-eosin and analyzed by a blinded grader. RESULTS: Polytrauma induced persistent changes in immune function at baseline and to secondary infection. Pneumonia after injury resulted in increased mortality (60% vs. 5% p < 0.01). Blood neutrophils from PT mice had higher resting (unstimulated) ROS production than in naive animals (p < 0.02) demonstrating priming of the neutrophils following PT. After intratracheal HKPA injection, bronchoalveolar lavage PMNs from injured mice had higher ROS production compared with naive mice (p < 0.01), demonstrating an overexuberant immunopathologic response of neutrophils following PT. CONCLUSION: Polytrauma primes neutrophils and causes immunopathologic PMN ROS production, increased lung injury and susceptibility to secondary bacterial pneumonia. These results suggest that trauma-induced immune dysfunction can cause immunopathologic response to secondary infection and suggests neutrophil-mediated pulmonary damage as a therapeutic target for posttrauma pneumonia.

The association between state-level abortion restrictions and maternal mortality in the United States, 1995-2017.

OBJECTIVE: To explore the relationship between abortion restrictions and maternal mortality in the United States. STUDY DESIGN: This was a retrospective study examining maternal mortality in the United States from 1995 to 2017. We used the Global Health Data Exchange and the Centers for Disease Control and Prevention WONDER databases to extract maternal mortality data for all 50 states for each year from 1995 to 2017. We categorized states as restrictive, neutral, or protective of abortion access according to policy information published by the Guttmacher Institute. We assessed associations between abortion restrictions and maternal mortality ratios (maternal deaths per 100,000 live births). RESULTS: In 1995, the mean maternal mortality ratios were similar across all groups of states (Restrictive 12.6, 95% CI 11.4-13.6; Neutral 12.2, 95% CI 10.9-13.4; Protective 10.9, 95% CI 9.6-11.9). Maternal mortality ratios increased for each group of states over time and in 2017, the mean maternal mortality ratio was higher in restrictive states than in protective states (Restrictive 28.5, 95% CI 20.7-35.1; Neutral 22.9, 95% CI 16.1-28.6; Protective 15.7, 95% CI 10.7-19.9). Regressions accounting for policy, state and year showed a statistically significant increase in maternal mortality ratios in restrictive states relative to neutral states (1.06, 95% CI 1.01-1.11) and a non-significant decrease associated with protective states (0.89, 95% CI 0.78-1.01). CONCLUSIONS: States that restrict abortion have higher maternal mortality than states that either protect or are neutral towards abortion. Further investigation is needed to determine how abortion restrictions are associated with increased maternal mortality. IMPLICATIONS: The association between abortion restrictions and maternal mortality may reflect the overall legislative priorities of individual states as restrictive states are less likely to pass proactive legislation demonstrated to improve maternal outcomes.

Dysregulation of the Leukocyte Signaling Landscape during Acute COVID-19.

The global COVID-19 pandemic has claimed the lives of more than 450,000 US citizens. Dysregulation of the immune system underlies the pathogenesis of COVID-19, with inflammation mediated local tissue injury to the lung in the setting of suppressed systemic immune function. To define the molecular mechanisms of immune dysfunction in COVID-19 we utilized a systems immunology approach centered on the circulating leukocyte phosphoproteome measured by mass cytometry. COVID-19 is associated with wholesale activation of a broad set of signaling pathways across myeloid and lymphoid cell populations. STAT3 phosphorylation predominated in both monocytes and T cells and was tightly correlated with circulating IL-6 levels. High levels of STAT3 phosphorylation was associated with decreased markers of myeloid cell maturation/activation and decreased ex-vivo T cell IFN-gamma production, demonstrating that during COVID-19 dysregulated cellular activation is associated with suppression of immune effector cell function. Collectively, these data reconcile the systemic inflammatory response and functional immunosuppression induced by COVID-19 and suggest STAT3 signaling may be the central pathophysiologic mechanism driving immune dysfunction in COVID-19.

Equity on the frontlines of trauma surgery: An #EAST4ALL roundtable.

BACKGROUND: Inequity exists in surgical training and the workplace. The Eastern Association for the Surgery of Trauma (EAST) Equity, Quality, and Inclusion in Trauma Surgery Ad Hoc Task Force (EAST4ALL) sought to raise awareness and provide resources to combat these inequities. METHODS: A study was conducted of EAST members to ascertain areas of inequity and lack of inclusion. Specific problems and barriers were identified that hindered inclusion. Toolkits were developed as resources for individuals and institutions to address and overcome these barriers. RESULTS: Four key areas were identified: (1) harassment and discrimination, (2) gender pay gap or parity, (3) implicit bias and microaggressions, and (4) call-out culture. A diverse panel of seven surgeons with experience in overcoming these barriers either on a personal level or as a chief or chair of surgery was formed. Four scenarios based on these key areas were proposed to the panelists, who then modeled responses as allies. CONCLUSION: Despite perceived progress in addressing discrimination and inequity, residents and faculty continue to encounter barriers at the workplace at levels today similar to those decades ago. Action is needed to address inequities and lack of inclusion in acute care surgery. The EAST is working on fostering a culture that minimizes bias and recognizes and addresses systemic inequities, and has provided toolkits to support these goals. Together, we can create a better future for all of us.

Universal background checks for handgun purchases can reduce homicide rates of African Americans.

BACKGROUND: Federal law requires background checks for firearms purchased from licensed dealers, but states can extend requirements to private sales of handguns and purchases at gun shows (universal background checks for handguns [UBC-HG]). Although firearm homicide disproportionately affects African Americans, little is known about how UBG-HG impacts African Americans. We hypothesized that implementation of UBC-HG would reduce rates of firearm homicide of African Americans. METHODS: We collected Centers for Disease Control firearm homicide counts for African American and white populations in the 50 states, 1999 to 2017. Laws were drawn from the State Firearm Laws Database. The exposure and outcome of interest were UBC-HG adoption and firearm homicide. We included non-Hispanic African American and non-Hispanic white populations. We used Poisson regression to perform a differences-in-differences analysis. A categorical variable for state accounted for time-stable state characteristics. We controlled for year to account for trends over time unrelated to policy. We controlled for state-specific, time-variable factors, including median household income, population younger than 25 years or 65 years or older, alcohol consumption, and count of firearm laws (UBC-HG excluded). Standard errors were adjusted for clustering at the state level. RESULTS: The firearm homicide rate among whites was 1.8 per 100,000 (interquartile range, 1.2-2.7) ranging from 1.4 in 2011 to 1.8 in 2016. The firearm homicide rate was 15.6 per 100,000 (interquartile range, 11.6-21.0) among African Americans, ranging from 14.0 in 2009 to 19.6 in 2017. While no significant difference in firearm homicides among whites (incidence rate ratio, 0.93; 95% confidence interval, 0.73-1.20) was appreciated, the passage of UBC-HG was associated with an 19% decrease in African Americans firearm homicides (incidence rate ratio, 0.81; 95% confidence interval, 0.70-0.94; p = 0.006). CONCLUSION: Implementing UBC-HG was associated with decreased firearm homicides among African Americans-the population most at risk. Expanding UBC-HG may be an effective approach to reducing racial disparities in firearm homicides. LEVEL OF EVIDENCE: Epidemiological, level III.

Firearm laws and illegal firearm flow between US states.

BACKGROUND: Considerable variation in firearm legislation exists. Prior studies show an association between stronger state laws and fewer firearm deaths. We hypothesized that firearms would flow from states with weaker laws to states with stronger laws based on proximity and population. METHODS: Crime gun trace data from 2015 to 2017 was accessed from the Bureau of Alcohol, Tobacco, Firearms and Explosives and compared with the count and composition of firearm legislation in 2015 among the contiguous 48 states. Additional independent variables included population, median household income, distance, and presence or absence of a shared border. We used Exponential Random Graph Models to identify predictors of traced firearm transfers between origin and destination states. RESULTS: After controlling for network structure, firearm laws in origin states were associated with fewer traced firearm transfers (incidence rate ratio [IRR], 0.88; 95% confidence interval [CI], 0.83-0.93; p < 0.001). Conversely, more firearm laws in destination states were associated with more traced firearm transfers (IRR, 1.10; 95% CI, 1.06-1.15; p < 0.001). Larger population at the origin was associated with increased transfers (IRR, 1.38; 95%CI, 1.27-1.50; p < 0.001), as was larger population at the destination state (IRR, 1.45; 95% CI, 1.35-1.56; p < 0.001). Greater distance was associated with fewer transfers (for each 1,000 km; IRR, 0.35; 95% CI, 0.27-0.46; p < 0.001), and transfers were greater between adjacent states (IRR, 2.49; 95% CI, 1.90-3.27; p < 0.001). CONCLUSION: State firearm legislation has a significant impact on gun trafficking even after controlling for network structure. States with stricter firearm legislation are negatively impacted by states with weaker regulations, as crime guns flow from out-of-state. LEVEL OF EVIDENCE: Epidemiologic, level III.