Project description:Importance:Firearm laws in one state may be associated with increased firearm death rates from homicide and suicide in neighboring states. Objective:To determine whether counties located closer to states with lenient firearm policies have higher firearm death rates. Design, Setting, and Participants:This cross-sectional study of firearm death rates by county for January 2010 to December 2014 examined data from the US Centers for Disease Control and Prevention for firearm suicide and homicide decedents for 3108 counties in the 48 contiguous states of the United States. Exposures:Each county was assigned 2 scores, a state policy score (range, 0-12) based on the strength of its state firearm laws, and an interstate policy score (range, -1.33 to 8.31) based on the sum of population-weighted and distance-decayed policy scores for all other states. Counties were divided into those with low, medium, and high home state and interstate policy scores. Main Outcomes and Measures:County-level rates of firearm, nonfirearm, and total homicide and suicide. With multilevel Bayesian spatial Poisson models, we generated incidence rate ratios (IRR) comparing incidence rates between each group of counties and the reference group, counties with high home state and high interstate policy scores. Results:Stronger firearm laws in a state were associated with lower firearm suicide rates and lower overall suicide rates regardless of the strength of the other states' laws. Counties with low state scores had the highest rates of firearm suicide. Rates were similar across levels of interstate policy score (low: IRR, 1.34; 95% credible interval [CI], 1.11-1.65; medium: IRR, 1.36, (95% CI, 1.15-1.65; and high: IRR, 1.43; 95% CI, 1.20-1.73). Counties with low state and low or medium interstate policy scores had the highest rates of firearm homicide. Counties with low home state and interstate scores had higher firearm homicide rates (IRR, 1.38; 95% CI, 1.02-1.88) and overall homicide rates (IRR, 1.32; 95% CI, 1.03-1.67). Counties in states with low firearm policy scores had lower rates of firearm homicide only if the interstate firearm policy score was high. Conclusions and Relevance:Strong state firearm policies were associated with lower suicide rates regardless of other states' laws. Strong policies were associated with lower homicide rates, and strong interstate policies were also associated with lower homicide rates, where home state policies were permissive. Strengthening state firearm policies may prevent firearm suicide and homicide, with benefits that may extend beyond state lines.
Project description:BackgroundFirearm injuries are a major cause of mortality in the USA. Few recent studies have simultaneously examined the impact of multiple state gun laws to determine their independent association with homicide and suicide rates.ObjectiveTo examine the relationship between state firearm laws and overall homicide and suicide rates at the state level across all 50 states over a 26-year period.DesignUsing a panel design, we analyzed the relationship between 10 state firearm laws and total, age-adjusted homicide and suicide rates from 1991 to 2016 in a difference-in-differences, fixed effects, multivariable regression model. There were 1222 observations for homicide analyses and 1300 observations for suicide analyses.ParticipantsPopulations of all US states.Main measuresThe outcome measures were the annual age-adjusted rates of homicide and suicide in each state during the period 1991-2016. We controlled for a wide range of state-level factors.Key resultsUniversal background checks were associated with a 14.9% (95% CI, 5.2-23.6%) reduction in overall homicide rates, violent misdemeanor laws were associated with a 18.1% (95% CI, 8.1-27.1%) reduction in homicide, and "shall issue" laws were associated with a 9.0% (95% CI, 1.1-17.4%) increase in homicide. These laws were significantly associated only with firearm-related homicide rates, not non-firearm-related homicide rates. None of the other laws examined were consistently related to overall homicide or suicide rates.ConclusionsWe found a relationship between the enactment of two types of state firearm laws and reductions in homicide over time. However, further research is necessary to determine whether these associations are causal ones.
Project description:ImportanceFirearm injury is the second leading cause of death in the United States for children and young adults. The risk of unintentional and self-inflicted firearm injury is lower when all household firearms are stored locked.ObjectiveTo estimate the reduction in youth firearm suicide and unintentional firearm mortality that would result if more adults in households with youth stored household guns locked.Design, setting, and participantsA modeling study using Monte Carlo simulation of youth firearm suicide and unintentional firearm mortality in 2015. A simulated US national sample of firearm-owning households where youth reside was derived using nationally representative rates of firearm ownership and storage and population data from the US Census to test a hypothetical intervention, safe storage of firearms in the home, on youth accidental death and suicide. Data analyses were performed from August 3, 2017, to January 9, 2018.ExposuresObserved and counterfactual household-level safe firearm storage (ie, storing all firearms locked), the latter estimated by varying the probability that a hypothetical intervention increased safe firearm storage beyond that observed in 2015.Main outcomes and measuresObserved and counterfactual counts of firearm suicide and unintentional firearm mortality among youth aged 0 to 19 years, the latter estimated by incorporating an empirically based estimate of the mortality benefit expected from additional safe storage (beyond that observed in 2015).ResultsA hypothetical intervention among firearm owners residing with children with a 20% probability of motivating these owners to lock all household firearms was significantly associated with a projected reduction in youth firearm mortality (median incidence rate ratio = 0.90; interquartile range, 0.87-0.93). In the overall model, 6% to 32% of deaths were estimated to be preventable depending on the probability of motivating safer storage.Conclusions and relevanceResults of this modeling study suggest that a relatively modest uptake of a straightforward safe storage recommendation-lock all household firearms-could result in meaningful reductions in firearm suicide and unintentional firearm fatalities among youth. Approaches that will motivate additional parents to store firearms safely are needed.
Project description:BackgroundSubstance-related interactions with the criminal justice system are a potential touchpoint to identify people at risk for firearm violence. We used an agent-based model to simulate the change in firearm violence after disqualifying people from owning a firearm given prior alcohol- and drug-related misdemeanors.MethodsWe created a population of 800,000 agents reflecting a 15% sample of the adult New York City population.ResultsDisqualification from purchasing firearms for 5 years after an alcohol-related misdemeanor conviction reduced population-level rates of firearm homicide by 1.0% [95% CI 0.4-1.6%] and suicide by 3.0% [95% CI 1.9-4.0%]. Disqualification based on a drug-related misdemeanor conviction reduced homicide by 1.6% [95% CI 1.1-2.2%] and suicide by 4.6% [95% CI 3.4-5.8%]. Reductions were generally 2 to 8 times larger for agents meeting the disqualification criteria.ConclusionsDenying firearm access based on a history of drug and alcohol misdemeanors may reduce firearm violence among the high-risk group. Enactment of substance use-related firearms denial criteria needs to be balanced against concerns about introducing new sources of disenfranchisement among already vulnerable populations.
Project description:BackgroundFirearm-related violence is a leading cause of mortality in the United States (US). Prior research suggests that public policy plays a role in firearm mortality, but the role of healthcare resources (physicians, insurance coverage) within the US policy context has not yet been studied.ObjectiveTo examine how healthcare resources and social/firearm policy affect firearm-related suicide and homicide rates in the US.DesignLongitudinal, ecological study.SettingUS.ParticipantsUS states from 2012 to 2016 (N = 242).MeasurementThe outcome variables were age-adjusted, firearm-related suicide and homicide rates. Predictor variables were healthcare resources (physicians, Medicaid benefits generosity) and policy context (social policy, firearm policy) with covariates for sociodemographic factors.ResultsHealthcare provider variables did not have significant associations to firearm-related suicide or homicide. In fully saturated models, more worker protection laws, greater average population density, more alcohol regulation, and more firearm prohibition policies were associated with fewer firearm-related suicides. Higher generosity of Medicaid benefits was associated with fewer firearm-related homicides. Poverty rate was a predictor of both outcomes.LimitationsThis state-level study cannot make individual-level inferences. Only proxy variables were available for measuring gun ownership and actual gun ownership rates may not have been ideally captured at the state level.ConclusionsAt the state level, there are protective associations of certain social, healthcare, and firearm policies to firearm-related suicide and homicide rates. Healthcare resources play a role in population-level firearm outcomes but alone are not sufficient to decrease firearm-related homicide or suicide.
Project description:BackgroundFirearm homicides occur less frequently in US states with more firearm control laws. However, firearms are easily transported across state lines, and laws in one location may affect firearm violence in another. This study examined associations between within-state firearm laws and firearm homicide while accounting for interference from laws in other nearby states.MethodsThe units of analysis were 3,107 counties in the 48 contiguous US states, arrayed in 15 yearly panels for 2000 to 2014 (n = 46,605). The dependent measure was firearm homicides accessed from the Centers for Disease Control and Prevention (CDC) Compressed Mortality Data. The main independent measures were counts of firearm laws and the proportion of laws within categories (e.g., background checks, child access prevention laws). We calculated these measures for interstate laws using a geographic gravity function between county centroids. Bayesian conditional autoregressive Poisson models related within-state firearm laws and interstate firearm laws to firearm homicides.ResultsThere were 172,726 firearm homicides in the included counties over the 15 years. States had between 3 and 100 firearm laws. Within-state firearm laws (incidence rate ratio [IRR] = 0.995, 95% confidence interval [CI] = 0.992, 0.997) and interstate firearm laws (IRR = 0.993, 95% CI = 0.990, 0.996) were independently associated with fewer firearm homicides, and associations for within-state laws were strongest where interstate laws were weakest.ConclusionsAdditional firearm laws are associated with fewer firearm homicides both within the states where the laws are enacted and elsewhere in the United States. Interference from interstate firearm laws may bias associations for studies of within-state laws and firearm homicide.
Project description:BackgroundIdentifying community characteristics associated with firearm assault could facilitate prevention. We investigated the effect of community firearm dealer and alcohol outlet densities on individual risk of firearm assault injury.MethodsIn this density-sampled case-control study of Californians, January 2005-September 2015, cases comprised all residents with a fatal or nonfatal firearm assault injury. For each month, we sampled controls from the state population in a 4:1 ratio with cases. Exposures were monthly densities of county-level pawn and nonpawn firearm dealers and ZIP code-level off-premises alcohol outlets and bars and pubs ("bars/pubs"). We used case-control-weighted G-computation to estimate risk differences (RD) statewide and among younger Black men, comparing observed exposure densities to hypothetical interventions setting these densities to low. We estimated additive interactions between firearm and alcohol retailer density. Secondary analyses examined interventions targeted to high exposure density or outcome burden areas.ResultsThere were 67,850 cases and 268,122 controls. Observed (vs. low) densities of pawn firearm dealers and off-premises alcohol outlets were individually associated with elevated monthly risk of firearm assault per 100,000 people (RD pawn dealers : 0.06, 95% CI: 0.05, 0.08; RD off-premises outlets : 0.01, 95% CI: 0.01, 0.03), but nonpawn firearm dealer and bar/pub density were not; models targeting only areas with the highest outcome burden were similar. Among younger Black men, estimates were larger. There was no interaction between firearm and alcohol retailer density.ConclusionsOur results are consistent with the hypothesis that limiting pawn firearm dealers and off-premises alcohol outlet densities can reduce interpersonal firearm violence.
Project description:Canada implemented a series of laws regulating firearms including background checks and licensing, references, psychological questionnaires, prohibition of paramilitary style rifles, and magazine capacity restrictions in order to decrease the incidences and deaths from mass shootings. The associated effects of these laws were examined over the years 1974 to 2020. A model was constructed using difference-in-differences analysis of firearms and non-firearms mass homicide incidences and death rates. Mass homicides were defined as a homicide due to one event involving three or more deaths. Incidence rates of mass homicide by firearm were found to be 0.11 (95%CI 0.08, 0.14) per million compared to a non-firearm mass homicide rate of 0.12 (95% CI 0.10, 0.15) per million. Mass homicide death rates by firearm were found to be 0.39 (95% CI 0.29, 0.49) per million compared to a non-firearm mass homicide rate of 0.47 (95% CI 0.34, 0.61) per million. Overall, there is a gradual declining trend in the incidence of mass homicide by firearm (IRR 0.97 (95% CI 0.96, 0.98)) and by non-firearm (IRR 0.97 (95% CI 0.97, 0.98)). The decline in mass homicide death rate by firearm and non-firearm is IRR 0.96 (95% CI 0.95, 0.97), and IRR 0.97 (95% CI 0.96, 0.98) respectively. No specific associated decrease in mass homicide incidence rates or death rates with firearms legislation was found after the implementation of background checks and prohibition of full auto firearms in 1980, by the implementation of references and psychological questionnaires in 1994, by the restriction of magazine capacity in 1994, the prohibition of paramilitary rifles in 1994, or licensing in 2001.
Project description:BackgroundPrior to the establishment of the uniform drinking age of 21 in the United States, many states permitted legal purchase of alcohol at younger ages. Lower drinking ages were associated with several adverse outcomes, including elevated rates of suicide and homicide among youth. The objective of this study is to examine whether individuals who were legally permitted to drink prior to age 21 remained at elevated risk in adulthood.MethodsAnalysis of data from the U.S. Multiple Cause of Death files, 1990 to 2004, combined with data on the living population from the U.S. Census and American Community Survey. The assembled data contained records on over 200,000 suicides and 130,000 homicides for individuals born between 1949 and 1972, the years during which the drinking age was in flux. Logistic regression models were used to evaluate whether adults who were legally permitted to drink prior to age 21 were at elevated risk for death by these causes. A quasi-experimental analytical approach was employed, which incorporated state and birth-year fixed effects to account for unobserved covariates associated with policy exposure.ResultsIn the population as a whole, we found no association between minimum drinking age and homicide or suicide. However, significant policy-by-sex interactions were observed for both outcomes, such that women exposed to permissive drinking age laws were at higher risk for both suicide (OR = 1.12, 95% CI: 1.05, 1.18, p = 0.0003) and homicide (OR = 1.15, 95% CI: 1.04, 1.25, p = 0.0028). Effect sizes were stronger for the portion of the cohort born after 1960, whereas no significant effects were observed for women born prior to 1960.ConclusionsLower drinking ages may result in persistent elevated risk for suicide and homicide among women born after 1960. The national drinking age of 21 may be preventing about 600 suicides and 600 homicides annually.