Z-Score Burden Metric: A Method for Assessing Burden of Injury and Disease.

INTRODUCTION: Traditional methods of summarizing burden of disease have limitations in terms of identifying communities within a population that are in need of prevention and intervention resources. This paper proposes a new method of burden assessment for use in guiding these decisions. METHODS: This new method for assessing burden utilizes the sum of population-weighted age-specific z-scores. This new Z-Score Burden Metric was applied to firearm-related deaths in North Carolina counties using 2010‒2017 North Carolina Violent Death Reporting System data. The Z-Score Burden Metric consists of 4 measures describing various aspects of burden. The Z-Score Burden Metric Overall Burden Measure was compared with 2 traditional measures (unadjusted and age-adjusted death rates) for each county to assess similarities and differences in the relative burden of firearm-related death. RESULTS: Of all 100 North Carolina counties, 73 met inclusion criteria (≥5 actual and expected deaths during the study period in each age strata). Ranking by the Overall Burden Measure produced an ordering of counties different from that of ranking by traditional measures. A total of 8 counties (11.0%) differed in burden rank by at least 10% when comparing the Overall Burden Measure with age-adjusted and unadjusted rates. All the counties with large differences between the measures were substantially burdened by firearm-related death. CONCLUSIONS: The use of the Z-Score Burden Metric provides an alternative way of measuring realized community burden of injury while still facilitating comparisons between communities with different age distributions. This method can be used for any injury or disease outcome and may help to prioritize the allocation of resources to communities suffering high burdens of injury and disease.

Linking Emergency Medical Services and Emergency Department Data to Improve Overdose Surveillance in North Carolina.

INTRODUCTION: Linking emergency medical services (EMS) data to emergency department (ED) data enables assessing the continuum of care and evaluating patient outcomes. We developed novel methods to enhance linkage performance and analysis of EMS and ED data for opioid overdose surveillance in North Carolina. METHODS: We identified data on all EMS encounters in North Carolina during January 1-November 30, 2017, with documented naloxone administration and transportation to the ED. We linked these data with ED visit data in the North Carolina Disease Event Tracking and Epidemiologic Collection Tool. We manually reviewed a subset of data from 12 counties to create a gold standard that informed developing iterative linkage methods using demographic, time, and destination variables. We calculated the proportion of suspected opioid overdose EMS cases that received International Classification of Diseases, Tenth Revision, Clinical Modification diagnosis codes for opioid overdose in the ED. RESULTS: We identified 12 088 EMS encounters of patients treated with naloxone and transported to the ED. The 12-county subset included 1781 linkage-eligible EMS encounters, with historical linkage of 65.4% (1165 of 1781) and 1.6% false linkages. Through iterative linkage methods, performance improved to 91.0% (1620 of 1781) with 0.1% false linkages. Among statewide EMS encounters with naloxone administration, the linkage improved from 47.1% to 91.1%. We found diagnosis codes for opioid overdose in the ED among 27.2% of statewide linked records. PRACTICE IMPLICATIONS: Through an iterative linkage approach, EMS-ED data linkage performance improved greatly while reducing the number of false linkages. Improved EMS-ED data linkage quality can enhance surveillance activities, inform emergency response practices, and improve quality of care through evaluating initial patient presentations, field interventions, and ultimate diagnoses.

A Mixed-Methods Comparison of a National and State Opioid Overdose Surveillance Definition.

OBJECTIVES: We assessed the differences between the first version of the Centers for Disease Control and Prevention (CDC) opioid surveillance definition for suspected nonfatal opioid overdoses (hereinafter, CDC definition) and the North Carolina Disease Event Tracking and Epidemiologic Collection Tool (NC DETECT) surveillance definition to determine whether the North Carolina definition should include additional International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) codes and/or chief complaint keywords. METHODS: Two independent reviewers retrospectively reviewed data on North Carolina emergency department (ED) visits generated by components of the CDC definition not included in the NC DETECT definition from January 1 through July 31, 2018. Clinical reviewers identified false positives as any ED visit in which available evidence supported an alternative explanation for patient presentation deemed more likely than an opioid overdose. After individual assessment, reviewers reconciled disagreements. RESULTS: We identified 2296 ED visits under the CDC definition that were not identified under the NC DETECT definition during the study period. False-positive rates ranged from 2.6% to 41.4% for codes and keywords uniquely identifying ≥10 ED visits. Based on uniquely identifying ≥10 ED visits and a false-positive rate ≤10.0%, 4 of 16 ICD-10-CM codes evaluated were identified for NC DETECT definition inclusion. Only 2 of 25 keywords evaluated, "OD" and "overdose," met inclusion criteria to be considered a meaningful addition to the NC DETECT definition. PRACTICE IMPLICATIONS: Quantitative and qualitative trends in coding and keyword use identified in this analysis may prove helpful for future evaluations of surveillance definitions.

Estimating the international burden of sport-related death: a review of data sources.

INTRODUCTION: Despite detailed recommendations for sports injury data capture provided since the mid-1990s, international data collection efforts for sport-related death remains limited in scope. The purpose of this paper was to review the data sources available for studying sport-related death and describe their key features, coverage, accessibility and strengths and limitations. METHODS: The outcomes of interest for this review was death occurring as a result of participation in organised sport-related activity. Data sources used to enumerate death in sport were identified, drawing from the authors' knowledge/experience and review of key references from international organisations. The general purpose, case identification, structure, strengths and limitations of each source in relation to collection of data for sport-related death were summarised, drawing on examples from the international published literature to illustrate this application. RESULTS: Seven types of resources were identified for capturing deaths in sport. Data sources varied considerably in their ability to identify: participant status, sport relatedness of the death, types of sport-related deaths they capture, level of detail provided about the circumstances and medical care received. The most detailed sources were those that were dedicated to sports surveillance. Sport relatedness and type of sport may not be reliably captured by systems not dedicated to sports injury surveillance. Only one source permitted international comparisons and was limited to one sport (soccer). CONCLUSION: Data on sport-related death are currently collected across a wide variety of data sources. This review highlights the need for robust, comprehensive approaches with standardised methodologies enabling linkage between sources and international comparisons.

Catastrophic neurologic injuries in sport.

Tens of millions of children and adults participate in organized sport in the United States each year. Although uncommon, fatal and severe nonfatal brain and spine injuries can occur during these activities. These "catastrophic" injuries have been noted in contact sports such as football, rugby, and ice hockey, as well as in noncontact sports including baseball, cheerleading, swimming and diving, equestrian, gymnastics, pole vault, rodeo, snow skiing, snowboarding, and wrestling. They happen at all levels of play, from youth to professional. Among all sports, football has the highest number of fatal brain and cervical spine injuries. While these injuries are more frequent in high school football, the rate is higher amongst college football athletes. Patterns exist in the types of brain and spine injuries most often occurring as a result of traumatic impacts in sport, but incidence and mechanisms of injury vary dramatically between sports. Understanding these patterns is essential to informing prevention efforts; football, pole vault, and cheer are all examples of sports benefiting from successful catastrophic injury prevention efforts. Participating in sport provides many benefits to physical and mental health. Despite these benefits, rare devastating injuries can be traumatic for the athletes, their families, and communities and can raise safety concerns that may reduce participation in sport. Understanding and preventing these types of injuries are critical to fostering participation in sport and ensuring both children and adults reap the physical, social, and mental benefits of sport.

Disparities in access to trauma care in the United States: A population-based analysis.

BACKGROUND: Injury is a major contributor to morbidity and mortality in the United States. Accordingly, expanding access to trauma care is a Healthy People priority. The extent to which disparities in access to trauma care exist in the US is unknown. Our objective was to describe geographic, demographic, and socioeconomic disparities in access to trauma care in the United States. METHODS: Cross-sectional study of the US population in 2010 using small units of geographic analysis and validated estimates of population access to a Level I or II trauma center within 60minutes via ambulance or helicopter. We examined the association between geographic, demographic, and socioeconomic factors and trauma center access, with subgroup analyses of urban-rural disparities. RESULTS: Of the 309 million people in the US in 2010, 29.7 million lacked access to trauma care. Across the country, areas with higher income were significantly more likely to have access (OR 1.30, 95% CI 1.12-1.50), as were major cities (OR 2.13, 95% CI 1.25-3.62) and suburbs (OR 1.27, 95% CI 1.02-1.57). Areas with higher rates of uninsured (OR 0.09, 95% CI 0.07-0.11) and Medicaid or Medicare eligible patients (OR 0.69, 95% CI 0.59-0.82) were less likely to have access. Areas with higher proportions of blacks and non-whites were more likely to have access (OR 1.37, 95% CI 1.19-1.58), as were areas with higher proportions of Hispanics and foreign-born persons (OR 1.51, 95% CI 1.13-2.01). Overall, rurality was associated with significantly lower access to trauma care (OR 0.20, 95% CI 0.18-0.23). CONCLUSION: While the majority of the United States has access to trauma care within an hour, almost 30 million US residents do not. Significant disparities in access were evident for vulnerable populations defined by insurance status, income, and rurality.

Sex Disparities in Access to Acute Stroke Care: Can Telemedicine Mitigate this Effect?

BACKGROUND: Women have more frequent and severe ischemic strokes than men, and are less likely to receive treatment for acute stroke. Primary stroke centers (PSCs) have been shown to utilize treatment more frequently. Further, as telemedicine (TM) has expanded access to acute stroke care we sought to investigate the association between PSC, TM and access to acute stroke care in the state of Texas. METHODS: Texas hospitals and resources were identified from the 2009 American Hospital Association Annual Survey. Hospitals were categorized as: (1) stand-alone PSCs not using telemedicine for acute stroke care, (2) PSCs using telemedicine for acute stroke care (PSC-TM), (3) non-PSC hospitals using telemedicine for acute stroke care, or (4) non-PSC hospitals not using telemedicine for acute stroke care. The proportion of the population who could reach a PSC within 60 minutes was determined for stand-alone PSCs, PSC-TM, and non-PSCs using TM for stroke care. RESULTS: Overall, women were as likely to have 60-minute access to a PSC or PSC-TM as their male counterparts (POR 1.02, 95% CI 1.02-1.03). Women were also just as likely to have access to acute stroke care via PSC or PSC-TM or TM as men (POR 1.03, 95% CI 1.02-1.04). DISCUSSION: Our study found no sex disparities in access to stand alone PSCs or to hospitals using TM in the state of Texas. The results of this study suggest that telemedicine can be used as part of an inclusive strategy to improve access to care equally for men and women.

Reassessing the Stroke Belt: Using Small Area Spatial Statistics to Identify Clusters of High Stroke Mortality in the United States.

BACKGROUND AND PURPOSE: The stroke belt is described as an 8-state region with high stroke mortality across the southeastern United States. Using spatial statistics, we identified clusters of high stroke mortality (hot spots) and adjacent areas of low stroke mortality (cool spots) for US counties and evaluated for regional differences in county-level risk factors. METHODS: A cross-sectional study of stroke mortality was conducted using Multiple Cause of Death data (Centers for Disease Control and Prevention) to compute age-adjusted adult stroke mortality rates for US counties. Local indicators of spatial association statistics were used for hot-spot mapping. County-level variables were compared between hot and cool spots. RESULTS: Between 2008 and 2010, there were 393 121 stroke-related deaths. Median age-adjusted adult stroke mortality was 61.7 per 100 000 persons (interquartile range=51.4-74.7). We identified 705 hot-spot counties (22.4%) and 234 cool-spot counties (7.5%); 44.5% of hot-spot counties were located outside of the stroke belt. Hot spots had greater proportions of black residents, higher rates of unemployment, chronic disease, and healthcare utilization, and lower median income and educational attainment. CONCLUSIONS: Clusters of high stroke mortality exist beyond the 8-state stroke belt, and variation exists within the stroke belt. Reconsideration of the stroke belt definition and increased attention to local determinants of health underlying small area regional variability could inform targeted healthcare interventions.

The effects of telemedicine on racial and ethnic disparities in access to acute stroke care.

Racial and ethnic disparities have been previously reported in acute stroke care. We sought to determine the effect of telemedicine (TM) on access to acute stroke care for racial and ethnic minorities in the state of Texas. Data were collected from the US Census Bureau, The Joint Commission and the American Hospital Association. Access for racial and ethnic minorities was determined by summing the population that could reach a primary stroke centre (PSC) or telemedicine spoke within specified time intervals using validated models. TM extended access to stroke expertise by 1.5 million residents. The odds of providing 60-minute access via TM were similar in Blacks and Whites (prevalence odds ratios (POR) 1.000, 95% CI 1.000-1.000), even after adjustment for urbanization (POR 1.000, 95% CI 1.000-1.001). The odds of providing access via TM were also similar for Hispanics and non-Hispanics (POR 1.000, 95% CI 1.000-1.000), even after adjustment for urbanization (POR 1.000, 95% CI 1.000-1.000). We found that telemedicine increased access to acute stroke care for 1.5 million Texans. While racial and ethnic disparities exist in other components of stroke care, we did not find evidence of disparities in access to the acute stroke expertise afforded by telemedicine.

The Effect of Telemedicine on Access to Acute Stroke Care in Texas: The Story of Age Inequalities.

Background. Ischemic stroke is a time sensitive disease with the effectiveness of treatment decreasing over time. Treatment is more likely to occur at Primary Stroke Centers (PSC); thus rapid access to acute stroke care through stand-alone PSCs or telemedicine (TM) is vital for all Americans. The objective of this study is to determine if disparities exist in access to PSCs or the extended access to acute stroke care provided by TM. Methods. Data from the US Census Bureau and the 2010 Neilson Claritas Demographic Estimation Program, American Hospital Association annual survey, and The Joint Commission list of PSCs and survey response data for all hospitals in the state of Texas were used. Results. Over 64% of block groups had 60-minute ground access to acute stroke care. The odds of a block group having 60-minute access to acute stroke care decreased with age, despite adjustment for sex, race, ethnicity, socioeconomic status, urbanization, and total population. Conclusion. Our survey of Texas hospitals found that as the median age of a block group increased, the odds of having access to acute stroke care decreased.

Optimization modeling to maximize population access to comprehensive stroke centers.

OBJECTIVE: The location of comprehensive stroke centers (CSCs) is critical to ensuring rapid access to acute stroke therapies; we conducted a population-level virtual trial simulating change in access to CSCs using optimization modeling to selectively convert primary stroke centers (PSCs) to CSCs. METHODS: Up to 20 certified PSCs per state were selected for conversion to maximize the population with 60-minute CSC access by ground and air. Access was compared across states based on region and the presence of state-level emergency medical service policies preferentially routing patients to stroke centers. RESULTS: In 2010, there were 811 Joint Commission PSCs and 0 CSCs in the United States. Of the US population, 65.8% had 60-minute ground access to PSCs. After adding up to 20 optimally located CSCs per state, 63.1% of the US population had 60-minute ground access and 86.0% had 60-minute ground/air access to a CSC. Across states, median CSC access was 55.7% by ground (interquartile range 35.7%-71.5%) and 85.3% by ground/air (interquartile range 59.8%-92.1%). Ground access was lower in Stroke Belt states compared with non-Stroke Belt states (32.0% vs 58.6%, p = 0.02) and lower in states without emergency medical service routing policies (52.7% vs 68.3%, p = 0.04). CONCLUSION: Optimal system simulation can be used to develop efficient care systems that maximize accessibility. Under optimal conditions, a large proportion of the US population will be unable to access a CSC within 60 minutes.

Disparities in accessibility of certified primary stroke centers.

BACKGROUND AND PURPOSE: We examine whether the proportion of the US population with ≤60 minute access to Primary Stroke Centers (PSCs) varies based on geographic and demographic factors. METHODS: Population level access to PSCs within 60 minutes was estimated using validated models of prehospital time accounting for critical prehospital time intervals and existing road networks. We examined the association between geographic factors, demographic factors, and access to care. Multivariable models quantified the association between demographics and PSC access for the entire United States and then stratified by urbanicity. RESULTS: Of the 309 million people in the United States, 65.8% had ≤60 minute PSC access by ground ambulance (87% major cities, 59% minor cities, 9% suburbs, and 1% rural). PSC access was lower in stroke belt states (44% versus 69%). Non-whites were more likely to have access than whites (77% versus 62%), and Hispanics were more likely to have access than non-Hispanics (78% versus 64%). Demographics were not meaningfully associated with access in major cities or suburbs. In smaller cities, there was less access in areas with lower income, less education, more uninsured, more Medicare and Medicaid eligibles, lower healthcare utilization, and healthcare resources. CONCLUSIONS: There are significant geographic disparities in access to PSCs. Access is limited in nonurban areas. Despite the higher burden of cerebrovascular disease in stroke belt states, access to care is lower in these areas. Selecting demographic and healthcare factors is strongly associated with access to care in smaller cities, but not in other areas, including major cities.

Geographic access to acute stroke care in the United States.

BACKGROUND AND PURPOSE: Only 3% to 5% of patients with acute ischemic stroke receive intravenous recombinant tissue-type plasminogen activator (r-tPA) and <1% receive endovascular therapy. We describe access of the US population to all facilities that actually provide intravenous r-tPA or endovascular therapy for acute ischemic stroke. METHODS: We used US demographic data and intravenous r-tPA and endovascular therapy rates in the 2011 US Medicare Provider and Analysis Review data set. International Classification of Diseases-Ninth Revision codes 433.xx, 434.xx and 436 identified acute ischemic stroke cases. International Classification of Diseases-Ninth Revision code 99.10 defined intravenous r-tPA treatment and International Classification of Diseases-Ninth Revision code 39.74 defined endovascular therapy. We estimated ambulance response times using arc-Geographic Information System's network analyst and helicopter transport times using validated models. Population access to care was determined by summing the population contained within travel sheds that could reach capable hospitals within 60 and 120 minutes. RESULTS: Of 370,351 acute ischemic stroke primary diagnosis discharges, 14,926 (4%) received intravenous r-tPA and 1889 (0.5%) had endovascular therapy. By ground, 81% of the US population had access to intravenous-capable hospitals within 60 minutes and 56% had access to endovascular-capable hospitals. By air, 97% had access to intravenous-capable hospitals within 60 minutes and 85% had access to endovascular hospitals. Within 120 minutes, 99% of the population had access to both intravenous and endovascular hospitals. CONCLUSIONS: More than half of the US population has geographic access to hospitals that actually deliver acute stroke care but treatment rates remain low. These data provide a national perspective on acute stroke care and should inform the planning and optimization of stroke systems in the United States.

Impact of Telemedicine on Access to Acute Stroke Care in the State of Texas.

BACKGROUND: To examine the impact of telemedicine on access to acute stroke care and expertise in the state of Texas. METHODS: Texas hospitals were surveyed using a standard questionnaire and categorized as: (1) stand-alone Primary Stroke Centers not using telemedicine for acute stroke care, (2) Primary Stroke Centers using telemedicine for acute stroke care, (3) non-Primary Stroke Center hospitals using telemedicine for acute stroke care, or (4) non-Primary Stroke Center hospitals not using telemedicine for acute stroke care. Population data were obtained from the US Census Bureau and the Neilson Claritas Demographic Estimation Program. Access within 60 minutes to a designated facility was calculated at the block group level. RESULTS: Over 75% of Texans had 60-minute access to a stand-alone Primary Stroke Center. Including Primary Stroke Centers using telemedicine increased access by 6.5%. Adding non- Primary Stroke Centers that use telemedicine for acute stroke care provided 60-minute access for an additional 2% of Texans, leaving 16% of Texans without 60-minute access to acute stroke care. Approximately 62% of Texans had 60-minute access to more than one type of facility that provided acute stroke care. CONCLUSION: The use of telemedicine in the state of Texas brought 60-minute access to >2 million Texans who otherwise would not have had access to acute stroke expertise. Our findings demonstrate that using telemedicine for acute stroke has the ability to provide neurologically underserved areas access to acute stroke care.

Simulating changes to emergency care resources to compare system effectiveness.

OBJECTIVE: To apply systems optimization methods to simulate and compare the most effective locations for emergency care resources as measured by access to care. STUDY DESIGN AND SETTING: This study was an optimization analysis of the locations of trauma centers (TCs), helicopter depots (HDs), and severely injured patients in need of time-critical care in select US states. Access was defined as the percentage of injured patients who could reach a level I/II TC within 45 or 60 minutes. Optimal locations were determined by a search algorithm that considered all candidate sites within a set of existing hospitals and airports in finding the best solutions that maximized access. RESULTS: Across a dozen states, existing access to TCs within 60 minutes ranged from 31.1% to 95.6%, with a mean of 71.5%. Access increased from 0.8% to 35.0% after optimal addition of one or two TCs. Access increased from 1.0% to 15.3% after optimal addition of one or two HDs. Relocation of TCs and HDs (optimal removal followed by optimal addition) produced similar results. CONCLUSIONS: Optimal changes to TCs produced greater increases in access to care than optimal changes to HDs although these results varied across states. Systems optimization methods can be used to compare the impacts of different resource configurations and their possible effects on access to care. These methods to determine optimal resource allocation can be applied to many domains, including comparative effectiveness and patient-centered outcomes research.

Characteristics and outcomes of injured patients presenting by private vehicle in a state trauma system.

BACKGROUND: Previous studies have demonstrated lower mortality among patients transported to single urban trauma centers by private vehicle (PV) compared with Emergency Medical Services (EMS). We sought to describe the characteristics and outcomes of injured patients transported by PV in a state trauma system compared to patients transported by EMS. METHODS: We performed a retrospective cohort study of state trauma registry data for patients admitted to all Pennsylvania trauma centers over 5 years (1/2003 to 12/2007). Our primary exposure of interest was prehospital mode of transport and our primary outcome of interest was in-hospital mortality. Unadjusted analyses were performed as were adjusted analyses controlling for injury severity. Data are presented as percents, odds ratios (ORs), and 95% confidence intervals. RESULTS: Of the 91132 patients analyzed, 9.6% were transported to the emergency department by PV and 90.4% by EMS. Overall Injury Severity Score (ISS) was 13.3 ± 11.0 (ISS for EMS 13.7 ± 11.3, PV 9.2 ± 7.1, P < .001), and 6.6% of patients died (EMS 7.1%, PV 1.5%, P < .001). After adjusting for injury severity, patients transported by EMS were more likely to die than PV patients (OR 1.9 [95% CI 1.5-2.4]). This effect persisted in blunt, penetrating, advanced life support, and basic life support subgroups, but not in the severely injured (ISS >15, ISS >25) subgroups. CONCLUSIONS: Nearly 10% of injured patients arrive at trauma centers by private vehicle. Transport of injured patients by EMS was associated with higher mortality than PV transport. This may reflect the effects of prehospital time, prehospital interventions, or other confounders.

Volume-outcome relationship in neurotrauma care.

OBJECT: A positive correlation between outcomes and the volume of patients seen by a provider has been supported by numerous studies. Volume-outcome relationships (VORs) have been well documented in the setting of both neurosurgery and trauma care and have shaped regionalization policies to optimize patient outcomes. Several authors have also investigated the correlation between patient volume and cost of care, known as the volume-cost relationship (VCR), with mixed results. The purpose of the present study was to investigate VORs and VCRs in the treatment of common intracranial injuries by testing the hypotheses that outcomes suffer at small-volume centers and costs rise at large-volume centers. METHODS: The authors performed a cross-sectional cohort study of patients with neurological trauma using the 2006 Nationwide Inpatient Sample, the largest nationally representative all-payer data set. Patients were identified using ICD-9 codes for subdural, subarachnoid, and extradural hemorrhage following injury. Transfers were excluded from the study. In the primary analysis the association between a facility's neurotrauma patient volume and patient survival was tested. Secondary analyses focused on the relationships between patient volume and discharge status as well as between patient volume and cost. Analyses were performed using logistic regression. RESULTS: In-hospital mortality in the overall cohort was 9.9%. In-hospital mortality was 14.9% in the group with the smallest volume of patients, that is, fewer than 6 cases annually. At facilities treating 6-11, 12-23, 24-59, and 60+ patients annually, mortality was 8.0%, 8.3%, 9.5%, and 10.0%, respectively. For these groups there was a significantly reduced risk of in-hospital mortality as compared with the group with fewer than 6 annual patients; the adjusted ORs (and corresponding 95% CIs) were 0.45 (0.29-0.68), 0.56 (0.38-0.81), 0.63 (0.44-0.90), and 0.59 (0.41-0.87), respectively. For these same groups (once again using < 6 cases/year as the reference), there were no statistically significant differences in either estimated actual cost or duration of hospital stay. CONCLUSIONS: A VOR exists in the treatment of neurotrauma, and a meaningful threshold for significantly improved mortality is 6 cases per year. Emergency and interfacility transport policies based on this threshold might improve national outcomes. Cost of care does not differ significantly with patient volume.

Unintentional firearm death across the urban-rural landscape in the United States.

BACKGROUND: Unintentional injuries are one of the leading causes of death in the United States. Many of these injuries are preventable, and unintentional firearm injuries, in particular, may be responsive to prevention efforts. We investigated the relationship between unintentional firearm death and urbanicity among adults. METHODS: This study was a retrospective analysis of national death certificate data. Unintentional adult firearm deaths in the United States from 1999 to 2006 were identified using the Multiple Cause of Death Data files from the National Center for Health Statistics. Decedents were assigned to a county of death and classified along an urban-rural continuum defined by population density and proximity to metropolitan areas. Total unintentional firearm death rates by county were analyzed in adjusted analyses using negative binomial regression. RESULTS: A total of 4,595 unintentional firearm injury deaths of adults occurred in the United States during the study period (a mean of 574.4 per year). Adjusted rates of unintentional firearm death showed increases from urban to rural counties. Americans in the most rural counties were significantly more likely to die of unintentional firearm deaths than those in the most urban counties (relative rate, 2.16; 95% confidence interval, 1.44-3.21, p = 0.002). CONCLUSION: Rates of unintentional firearm death are significantly higher in rural counties than in urban counties. Prevention strategies should be tailored to account for both geographic location and manner of firearm injury. LEVEL OF EVIDENCE: Epidemiologic study, level III.