Impact of Medicaid Expansion and Firearm Legislation on Cost of Firearm Injuries.

INTRODUCTION: Firearm injury-related hospitalizations in the U.S. cost $900 million annually. Before the Affordable Care Act, government insurance programs covered 41% of the costs. This study describes the impact of Affordable Care Act Medicaid expansion and state-level firearm legislation on coverage and costs for firearm injuries. METHODS: This cross-sectional study included 35,854,586 hospitalizations from 27 states in 2013 and 2016. Data analyses were performed in 2022. Firearm injuries were classified by mechanism: assault, unintentional, self-harm, or undetermined. The impact of the Affordable Care Act expansion was determined using difference-in-differences analysis. Differences in per capita costs between states with stronger and weak firearm legislation were compared using univariable and multivariable analyses. RESULTS: The authors identified 31,451 initial firearm injury-related hospitalizations. In states with weak firearm legislation, hospitalization costs per 100,000 residents were higher from unintentional ($25,834; p=0.04) and self-inflicted ($11,550; p=0.02) injuries; there were no state-level differences in assault or total per capita firearm-related hospitalization costs. Affordable Care Act expansion increased government coverage of costs by 15 percentage points (95% CI=3, 29) and decreased costs to uninsured/self-pay by 14 percentage points (95% CI=6, 21). In 2016, states with weak firearm legislation and no Affordable Care Act expansion had the highest proportion of hospitalization costs attributed to uninsured/self-pay patients (24%, 95% CI=15, 34). CONCLUSIONS: Affordable Care Act expansion increased government coverage of hospitalizations for firearm injuries. Unintentional and self-harm costs were significantly higher for states with weak firearm legislation. States with weak firearm legislation that did not expand Medicaid had the highest proportion of uninsured/self-pay patients.

Gentrification as a Factor in the Incidence of Firearm Injuries.

Importance: Firearm injuries are an epidemic in the US; more than 45 000 fatal injuries were recorded in 2020 alone. Gaining a deeper understanding of socioeconomic factors that may contribute to increasing firearm injury rates is critical to prevent future injuries. Objective: To explore whether neighborhood gentrification is associated with firearm injury incidence rates over time. Design, Setting, and Participants: This cross-sectional study used nationwide, urban US Census tract-level data on gentrification between 2010 and 2019 and firearm injuries data collected between 2014 and 2019. All urban Census tracts, as defined by Rural Urban Commuting Area codes 1 to 3, were included in the analysis, for a total of 59 379 tracts examined from 2014 through 2019. Data were analyzed from January 2022 through April 2023. Exposure: Gentrification, defined to be an area in a central city neighborhood with median housing prices appreciating over the median regional value and a median household income at or below the 40th percentile of the median regional household income and continuing for at least 2 consecutive years. Main Outcomes and Measures: The number of firearm injuries, controlling for Census tract population characteristics. Results: A total of 59 379 urban Census tracts were evaluated for gentrification; of these tracts, 14 125 (23.8%) were identified as gentrifying, involving approximately 57 million residents annually. The firearm injury incidence rate for gentrifying neighborhoods was 62% higher than the incidence rate in nongentrifying neighborhoods with similar sociodemographic characteristics (incidence rate ratio [IRR], 1.62; 95% CI, 1.56-1.69). In a multivariable analysis, firearm injury incidence rates increased by 57% per year for low-income Census tracts that did not gentrify (IRR, 1.57; 95% CI, 1.56-1.58), 42% per year for high-income tracts that did not gentrify (IRR, 1.42; 95% CI, 1.41-1.43), and 49% per year for gentrifying tracts (IRR, 1.49; 95% CI, 1.48-1.50). Neighborhoods undergoing the gentrification process experienced an additional 26% increase in firearm injury incidence above baseline increase experienced in neighborhoods not undergoing gentrification (IRR, 1.26; 95% CI, 1.23-1.30). Conclusions and Relevance: Results of this study suggest that gentrification is associated with an increase in the incidence of firearm injuries within gentrifying neighborhoods. Social disruption and residential displacement associated with gentrification may help explain this finding, although future research is needed to evaluate the underlying mechanisms. These findings support use of targeted firearm prevention interventions in communities experiencing gentrification.

The Impact of Redlining on Modern-Day Firearm Injuries: A Nationwide Study of Federal Policy.

OBJECTIVES: To evaluate whether exposure to the United States discriminatory housing practice of redlining, which occurred in over 200 cities in the 1930s, is associated with modern-day, community-level incidence of firearm injury. BACKGROUND: Firearm violence is a public health epidemic within the United States. Federal policies are crucial in both shaping and reducing the risk of firearm violence; identifying policies that might have contributed to risks also offers potential solutions. We analyzed whether 1930s exposure to the discriminatory housing practices that occurred in over 200 US cities was associated with the modern-day, community-level incidence of firearm injury. METHODS: We performed a nationwide retrospective cohort study between 2014 and 2018. Urban Zip Code Tabulation Areas (ZCTAs) historically exposed to detrimental redlining (grades C and D) were matched to unexposed ZCTAs based on modern-day population-level demographic characteristics (ie, age, Gini index, median income, percentage Black population, and education level). Incidence of firearm injury was derived from the Gun Violence Archive and aggregated to ZCTA level counts. Our primary outcome was the incidence of firearm injury, modeled using zero-inflated negative binomial regression. RESULTS: When controlling for urban firearm risk factors, neighborhoods with detrimental redlining were associated with 2.6 additional firearm incidents annually compared with nonredlined areas with similar modern-day risk factors. Over our study period, this accounts for an additional 23,000 firearm injuries. CONCLUSIONS: Historic, discriminatory Federal policies continue to impact modern-day firearm violence. Policies aimed at reversing detrimental redlining may offer an economic means to reduce firearm violence.

Hospital Costs and Fatality Rates of Traumatic Assaults by Mechanism in the US, 2016-2018.

Importance: Estimates of the total economic cost of firearm violence are important in drawing attention to this public health issue; however, studies that consider violence more broadly are needed to further the understanding of the extent to which such costs can be avoided. Objectives: To estimate the association of firearm assaults with US hospital costs and deaths compared with other assault types. Design, Setting, and Participants: The 2016-2018 US Nationwide Emergency Department Sample and National Inpatient Sample, Healthcare Cost and Utilization Project were used in this cross-sectional study of emergency department (ED) and inpatient admissions for assaults involving a firearm, sharp object, blunt object, or bodily force identified using International Statistical Classification of Diseases, Tenth Revision, Clinical Modification codes. Differences in ED and inpatient costs (2020 US dollars) across mechanisms were estimated using ordinary least-squares regression with and without adjustments for year and hospital, patient, and injury characteristics. The Centers for Disease Control and Prevention underlying cause of death data were used to estimate national death rates and hospital case-fatality rates across mechanisms. Cost analysis used a weighted sample. National death rates and hospital case-fatality rates used US resident death certificates, covering 976 million person-years. Hospital case-fatality rates also used nationally weighted ED records covering 2.7 million admissions. Data analysis was conducted from March 1, 2021, to March 31, 2022. Exposure: The primary exposure was the mechanism used in the assault. Main Outcomes and Measures: Emergency department and inpatient costs per record. National death rates and hospital case-fatality rates. Results: Overall, 2.4 million ED visits and 184 040 inpatient admissions for assault were included. Across all mechanisms, the mean age of the population was 32.7 (95% CI, 32.6-32.9) years in the ED and 36.4 (95% CI, 36.2-36.7) years in the inpatient setting; 41.9% (95% CI, 41.2%-42.5%) were female in the ED, and 19.1% (95% CI, 18.6%-19.6%) of inpatients were female. Most assaults recorded in the ED involved publicly insured or uninsured patients and hospitals in the Southern US. Emergency department costs were $678 (95% CI, $657-$699) for bodily force, $861 (95% CI, $813-$910) for blunt object, $996 (95% CI, $925-$1067) for sharp object, and $1388 (95% CI, $1254-$1522) for firearm assaults. Corresponding inpatient costs were $14 702 (95% CI, $14 178-$15 227) for bodily force, $17 906 (95% CI, $16 888-$18 923) for blunt object, $19 265 (95% CI, $18 475-$20 055) for sharp object, and $34 949 (95% CI, $33 654-$36 244) for firearm assaults. National death rates per 100 000 were 0.04 (95% CI, 0.03-0.04) for bodily force, 0.03 (95% CI, 0.03-0.03) for blunt object, 0.54 (95% CI, 0.52-0.55) for sharp object, and 4.40 (95% CI, 4.36-4.44) for firearm assaults. Hospital case fatality rates were 0.01% (95% CI, 0.009%-0.012%) for bodily force, 0.05% (95% CI, 0.04%-0.06%) for blunt object, 1.05% (95% CI, 1.00%-1.09%) for sharp object, and 15.26% (95% CI, 15.04%-15.49%) for firearm assaults. In regression analysis, ED costs for firearm assaults were 59% to 99% higher than costs for nonfirearm assaults, and inpatient costs were 67% to 118% higher. Conclusions and Relevance: The findings of this study suggest that it may be useful for policies aimed at reducing the costs of firearm violence to consider violence more broadly to understand the extent to which costs can be avoided.

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 $153 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.

Outcomes after ultramassive transfusion in the modern era: An Eastern Association for the Surgery of Trauma multicenter study.

BACKGROUND: Despite the widespread institution of modern massive transfusion protocols with balanced blood product ratios, survival for patients with traumatic hemorrhage receiving ultramassive transfusion (UMT) (defined as ≥20 U of packed red blood cells [RBCs]) in 24 hours) remains low and resource consumption remains high. Therefore, we aimed to identify factors associated with mortality in trauma patients receiving UMT in the modern resuscitation era. METHODS: An Eastern Association for the Surgery of Trauma multicenter retrospective study of 461 trauma patients from 17 trauma centers who received ≥20 U of RBCs in 24 hours was performed (2014-2019). Multivariable logistic regression and Classification and Regression Tree analysis were used to identify clinical characteristics associated with mortality. RESULTS: The 461 patients were young (median age, 35 years), male (82%), severely injured (median Injury Severity Score, 33), in shock (median shock index, 1.2; base excess, -9), and transfused a median of 29 U of RBCs, 22 U of fresh frozen plasma (FFP), and 24 U of platelets (PLT). Mortality was 46% at 24 hours and 65% at discharge. Transfusion of RBC/FFP ≥1.5:1 or RBC/PLT ≥1.5:1 was significantly associated with mortality, most pronounced for the 18% of patients who received both RBC/PLT and RBC/FFP ≥1.5:1 (odds ratios, 3.11 and 2.81 for mortality at 24 hours and discharge; both p < 0.01). Classification and Regression Tree identified that age older than 50 years, low initial Glasgow Coma Scale, thrombocytopenia, and resuscitative thoracotomy were associated with low likelihood of survival (14-26%), while absence of these factors was associated with the highest survival (71%). CONCLUSION: Despite modern massive transfusion protocols, one half of trauma patients receiving UMT are transfused with either RBC/FFP or RBC/PLT in unbalanced ratios ≥1.5:1, with increased associated mortality. Maintaining focus on balanced ratios during UMT is critical, and consideration of advanced age, poor initial mental status, thrombocytopenia, and resuscitative thoracotomy can aid in prognostication. LEVEL OF EVIDENCE: Prognostic, level III.

Incidence, Distribution, and Lethality of Firearm Injuries in California From 2005 to 2015.

Importance: Little is known about nonfatal firearm injuries in the United States, and national estimates based on emergency department samples may not be accurate. Objective: To describe the incidence and distribution of nonfatal firearm injuries and estimate case fatality ratios (CFRs) for firearm injuries by external cause of injury code within California overall and by race/ethnicity, including an assessment of trends over time and geographic variation within the state. Design, Setting, and Participants: This serial cross-sectional study used complete statewide data for firearm-related mortality, emergency department visits, and hospitalizations among California residents from January 1, 2005, through December 31, 2015, to analyze incidence, distribution, and CFRs of firearm injury. Data were analyzed from 2018 to 2019. Exposures: All individuals in California with a firearm injury based on International Classification of Diseases, Ninth Revision or International Statistical Classification of Diseases and Related Health Problems, Tenth Revision codes were included. Main Outcomes and Measures: Counts and rates of nonfatal firearm injuries overall and stratified by external cause, sex, and race/ethnicity; total and clinical CFRs. Clinical CFR was calculated based on individuals treated in emergency departments or hospitals. Results: Over the study period, there were 81 085 firearm-related emergency department visits and hospitalizations among individuals with a mean (SD) age of 27.5 (11.9) years, 72 567 (89.6%) of whom were men. Nonfatal firearm injuries in California decreased by 38.1% between 2005 and 2015, driven by a 46.4% decrease in assaultive injuries. Self-inflicted injuries and unintentional injuries remained relatively stable. The overall CFR for firearm injuries increased from 27.6% in 2005 to 32.2% in 2015 for a relative increase of 20.7%, while the clinical CFR remained stable between 7.0% and 9.0%. Conclusions and Relevance: These findings suggest that although the number of firearm injuries has decreased in California, the lethality of these injuries has not. Similar studies from other states could provide more information about these trends nationwide.

Preventing Firearm-Related Death and Injury.

Deaths and injuries from firearms are significant public health problems, and clinicians are in a unique position to identify risk among their patients and discuss the importance of safe firearm practices. Although clinicians may be ill-prepared to engage in such discussions, an adequate body of evidence is available for support, and patients are generally receptive to this type of discussion with their physician. Here, we provide an overview of existing research and recommended strategies for counseling and intervention to reduce firearm-related death and injury.

Readmission risk and costs of firearm injuries in the United States, 2010-2015.

BACKGROUND: In 2015 there were 36,252 firearm-related deaths and 84,997 nonfatal injuries in the United States. The longitudinal burden of these injuries through readmissions is currently underestimated. We aimed to determine the 6-month readmission risk and hospital costs for patients injured by firearms. METHODS: We used the Nationwide Readmission Database 2010-2015 to assess the frequency of readmissions at 6 months, and hospital costs associated with readmissions for patients with firearm-related injuries. We produced nationally representative estimates of readmission risks and costs. RESULTS: Of patients discharged following a firearm injury, 15.6% were readmitted within 6 months. The average annual cost of inpatient hospitalizations for firearm injury was over $911 million, 9.5% of which was due to readmissions. Medicare and Medicaid covered 45.2% of total costs for the 5 years, and uninsured patients were responsible for 20.1%. CONCLUSIONS: From 2010-2015, the average total cost of hospitalization for firearm injuries per patient was $32,700, almost 10% of which was due to readmissions within 6 months. Government insurance programs and the uninsured shouldered most of this.

Costs and Financial Burden of Initial Hospitalizations for Firearm Injuries in the United States, 2006-2014.

OBJECTIVES: To quantify the inflation-adjusted costs associated with initial hospitalizations for firearm-related injuries in the United States. METHODS: We used the Healthcare Cost and Utilization Project Nationwide Inpatient Sample to identify patients admitted for firearm-related injuries from 2006 to 2014. We converted charges from hospitalization to costs, which we inflation-adjusted to 2014 dollars. We used survey weights to create national estimates. RESULTS: Costs for the initial inpatient hospitalization totaled $6.61 billion. The largest proportion was for patients with governmental insurance coverage, totaling $2.70 billion (40.8%) and was divided between Medicaid ($2.30 billion) and Medicare ($0.40 billion). Self-pay individuals accounted for $1.56 billion (23.6%) in costs. CONCLUSIONS: From 2006 to 2014, the cost of initial hospitalizations for firearm-related injuries averaged $734.6 million per year. Medicaid paid one third and self-pay patients one quarter of the financial burden. These figures substantially underestimate true health care costs. Public health implications. Firearm-related injuries are costly to the US health care system and are particularly burdensome to government insurance and the self-paying poor.

Evolution of mosquito preference for humans linked to an odorant receptor.

Female mosquitoes are major vectors of human disease and the most dangerous are those that preferentially bite humans. A 'domestic' form of the mosquito Aedes aegypti has evolved to specialize in biting humans and is the main worldwide vector of dengue, yellow fever, and chikungunya viruses. The domestic form coexists with an ancestral, 'forest' form that prefers to bite non-human animals and is found along the coast of Kenya. We collected the two forms, established laboratory colonies, and document striking divergence in preference for human versus non-human animal odour. We further show that the evolution of preference for human odour in domestic mosquitoes is tightly linked to increases in the expression and ligand-sensitivity of the odorant receptor AaegOr4, which we found recognizes a compound present at high levels in human odour. Our results provide a rare example of a gene contributing to behavioural evolution and provide insight into how disease-vectoring mosquitoes came to specialize on humans.