Motor Vehicle Crash Mortality Research Articles

Association Between Geospatial Access to Trauma Center Care and Motor Vehicle Crash Mortality in the United States.

Motor vehicle crashes (MVCs) are a leading cause of preventable trauma death in the United States (US). Access to trauma center care is highly variable nationwide. The objective of this study was to measure the association between geospatial access to trauma center care and MVC mortality. This was a population-based study of MVC-related deaths that occurred in 3,141 US counties (2017-2020). ACS and state-verified level I-III trauma centers were mapped. Geospatial network analysis estimated the ground transport time to the nearest trauma center from the population-weighted centroid for each county. In this way, the exposure was the predicted access time to trauma center care for each county population. Hierarchical negative binomial regression measured the risk-adjusted association between predicted access time and MVC mortality, adjusting for population demographics, rurality, access to trauma resources, and state traffic safety laws. We identified 92,398 crash fatalities over the four-year study period. Trauma centers mapped included 217 level I, 343 level II, and 495 level III trauma centers. The median county predicted access time was 47 min (IQR 26-71 min). Median county MVC mortality was 12.5 deaths/100,000 person-years (IQR 7.4-20.3 deaths/100,000 person-years). After risk-adjustment, longer predicted access times were significantly associated with higher rates of MVC mortality (>60 min vs. <15 min; MRR 1.36; 95%CI 1.31-1.40). This relationship was significantly more pronounced in urban/suburban vs. rural/wilderness counties (p for interaction, <0.001). County access to trauma center care explained 16% of observed state-level variation in MVC mortality. Geospatial access to trauma center care is significantly associated with MVC mortality and contributes meaningfully to between-state differences in road traffic deaths. Efforts to improve trauma system organization should prioritize access to trauma center care to minimize crash fatalities. Level III, Epidemiological.

Ethnoracial Disparities in Rates of Non-Natural Causes of Death After the 2020 COVID-19 Outbreak in New York State

COVID-19 was associated with increases in non-natural cause mortality in the U.S., including deaths due to drug overdose, homicide, and motor vehicle crashes. Initial reports indicated higher rates of non-natural mortality among ethnoracial minority groups. This report aims to clarify these disparities by documenting trends in non-natural mortality across ethnoracial groups during the 2020 COVID-19 surge in New York State. We report monthly trends in non-natural cause mortality (overall and stratified by ethnoracial status) in New York State from January 2019 through December 2020, which included the COVID-19 onset in March 2020. Total mean monthly unintentional overdose rates per 100,000 increased from 17.45 (before surge: January 2019-February 2020) to 23.19 (after surge: March 2020-December 2020) (mean difference=5.73, 95% CI=3.82, 7.65; p<0.001).Mean monthly homicide death rates increased from 2.34 before surge to 3.55 after surge (mean difference=1.20, 95% CI=0.60, 1.81; p<0.001), with the increase seen primarily in the non-Latinx Black population. Although increasing unintentional overdose death rates before surge equally affected non-Latinx White, Latinx, and non-Latinx Black persons, they remained high for non-Latinx Black persons but dropped for the other 2 groups after the pandemic onset. None of the ethnoracial subgroups showed significant increases in suicide or motor vehicle crash death rates. Non-Latinx Black persons showed disproportionately high and sustained increased rates of unintentional overdose and homicide death rates after the 2020 COVID-19 surge in New York State. Fatality review and death scene investigation research is needed to better understand these disparities.

Association Between State-Level Access to Reproductive Care and Suicide Rates Among Women of Reproductive Age in the United States

Many states in the United States enforce restrictions to reproductive care, with access to abortion remaining a highly divisive issue. Denial of abortion is linked with heightened stress and anxiety among reproductive-aged women. However, no studies have tested whether access to reproductive care is linked to suicide. To evaluate whether state-level restrictions in access to reproductive care in the United States were associated with suicide rates among reproductive-aged women from 1974 to 2016. A longitudinal ecologic study with a difference-in-differences analysis assessed whether annual changes in the enforcement of state-level restrictions to reproductive care were related to annual state-level suicide rates vs rates of death due to motor vehicle crashes. Duration of follow-up varied between different states (range, 4-40 years), contingent on the first year that restrictions were implemented. Models controlled for year and state fixed effects and other relevant demographic and economic factors. Analyses were conducted between December 2021 and January 2022. Targeted Regulation of Abortion Providers (TRAP) laws index measuring state-year-level restrictions to reproductive care. Annual state-level suicide rates and motor vehicle crash death rates among reproductive-aged women (ages 20-34 years; target group) vs women of postreproductive age (ages 45-64 years; control group). Twenty-one US states enforced at least 1 TRAP law between 1974 and 2016. Annual rates of death by suicide ranged from 1.4 to 25.6 per 100 000 women of reproductive age to 2.7 to 33.2 per 100 000 women of postreproductive age during the study period (1974-2016). Annual motor vehicle crash death rates among women of reproductive age ranged from 2.4 to 42.9 per 100 000. Enforcement of TRAP laws was associated with higher suicide rates among reproductive-aged women (β = 0.17; 95% CI, 0.03 to 0.32; P = .02) but not women of postreproductive age (β = 0.06; 95% CI, -0.11 to 0.24; P = .47) nor to deaths due to motor vehicle crashes (β = 0.03, 95% CI, -0.04 to 0.11; P = .36). Among reproductive-aged women, the weighted average annual-state level suicide death rate when no TRAP laws were enforced was 5.5 per 100 000. Enforcement of a TRAP law was associated with a 5.81% higher annual rate of suicide than in pre-enforcement years. Findings remained significant when using alternative, broader indices of reproductive care access and different age categorizations. In this study with a difference-in-differences analysis of US women, restrictions on access to reproductive care from 1974 to 2016 were associated with suicide rates among reproductive-aged women. Given the limitations of the ecologic design of this study, further research is needed to assess whether current factors affecting access to reproductive care services are related to suicide risk among women of reproductive age and to inform suicide prevention strategies.

Direct Healthcare Costs of Moderate and Severe Work-Related Injuries: Estimates from the National Trauma Center of Qatar.

Work-related injuries (WRIs) are recognized as a leading cause of admission to the national trauma center of Qatar. A retrospective analysis of trauma registry data and electronic medical records was conducted on a cohort of all WRI patients who were admitted to the Hamad Trauma Center (HTC), in Doha, Qatar, between 2011 and 2017. A total of 3757 WRI patients were treated at the HTC over the 7-year study period. The overall cost for treatment was 124,671,431 USD (18 million USD per year), with a median cost of 19,071 USD. There was a strong positive correlation between the overall cost and hospital-stay cost (r2 = 0.949, p = 0.00001) and between the overall cost and procedure cost (r2 = 0.852, p = 0.00001). Motor vehicle crash (MVC) victims who wore seatbelts had significantly lower injury severity, hospital stay and median total costs. A comparison of patients by quartiles of the costs incurred showed that the proportions of MVC victims, pedestrian injuries and mortality were significantly higher in the fourth quartile when compared to other quartiles (p < 0.05). These findings suggest that investments in the primary prevention of work-related injuries from falls and MVCs, through proven interventions, should be priorities for occupational safety and health in Qatar.

Does geographic location matter for transportation risk behaviors among U.S. public high school students?

IntroductionTeen motor vehicle crash fatality rates differ by geographic location. Studies assessing teen transportation risk behaviors by location are inconclusive. Therefore, we explored the role of census region and metropolitan status for driving prevalence and four transportation risk behaviors among U.S. public high school students. MethodsData from 2015 and 2017 national Youth Risk Behavior Surveys were combined and analyzed. Multivariable models controlled for sex, age, race/ethnicity, grades in school, and school socioeconomic status. ResultsOverall, 41% of students did not always wear a seat belt. Students attending schools in the Northeast were 40% more likely than those in the Midwest to not always wear a seat belt. Among the 75% of students aged ≥16 years who had driven during the past 30 days, 47% texted/e-mailed while driving. Students in the Northeast were 20% less likely than those in the Midwest to text/e-mail while driving, and students attending suburban or town schools were more likely to text/e-mail while driving (20% and 30%, respectively) than students attending urban schools. Nineteen percent of students rode with a driver who had been drinking alcohol, and 7% of drivers aged ≥16 years drove when they had been drinking alcohol, with no significant differences by location for either alcohol-related behavior. ConclusionsWe found few differences in teen transportation risk behaviors by census region or metropolitan status. Age at licensure, time since licensure, driving experience, and the policy and physical driving environment might contribute more to variation in teen fatal crashes by location than differences in transportation risk behaviors. Regardless of location, teen transportation risk behaviors remain high. Future research could address developing effective strategies to reduce teen cell phone use while driving and enhancing community implementation of existing, effective strategies to improve seat belt use and reduce alcohol consumption and driving after drinking alcohol.

Traffic stops do not prevent traffic deaths.

Amid growing calls for police reform, it is imperative to reassess whether police actions designed to improve public safety are associated with injury prevention. This study aims to examine the relationship between the police traffic stops (PTSs) and motor vehicle crash (MVC) deaths at the state level. We hypothesize that increased PTSs would be associated with reduced MVC deaths. We retrospectively analyzed PTSs and MVC deaths at the state level from 2004 to 2016. Police traffic stops data were from 33 state patrols from the Stanford Open Policing Project. The MVC deaths data were collected from the National Highway Traffic Safety Administration. The vehicle miles traveled data were from the Federal Highway Administration Office of Highway Policy Information. All data were adjusted per 100 million vehicle miles traveled (100MVMT) and were analyzed as state-level time series cross-sectional data. The dependent variable was MVC deaths per 100MVMT, and the independent variable was number of PTSs per 100MVMT. We performed panel data analysis accounting for random and fixed state effects and changes over time. Thirty-three state patrols with 235 combined years were analyzed, with a total of 161,153,248 PTSs. The PTS rate varied by state and year. Nebraska had the highest PTS rate (3,637/100MVMT in 2004), while Arizona had the lowest (0.17/100MVMT in 2009). Motor vehicle crash deaths varied by state and year, with the highest death rate occurring in South Carolina in 2005 (2.2/100MVMT) and the lowest in Rhode Island in 2015 (0.57/100MVMT). After accounting for year and state-level variability, no association was found between PTS and the MVC death rates. State patrol traffic stops are not associated with reduced MVC deaths. Strategies to reduce death from MVC should consider alternative strategies, such as motor vehicle modifications, community-based safety initiatives, improved access to health care, or prioritizing trauma system. Retrospective epidemiological study, level IV.

Association between access to pediatric trauma care and motor vehicle crash death in children: An ecologic analysis of United States counties.

Access to pediatric trauma care is highly variable across the United States. The purpose of this study was to measure the association between pediatric trauma center care and motor vehicle crash (MVC) mortality in children (<15 years) at the US county level for 5 years (2014-2018). The exposure was defined as the highest level of pediatric trauma care present within each county: (1) pediatric trauma center, (2) adult level 1/2, (3) adult level 3, or (4) no trauma center. Pediatric deaths due to passenger vehicle crashes on public roads were identified from the NHTSA Fatality Analysis Reporting System. Hierarchical negative binomial modeling measured the relationship between highest level of pediatric trauma care and pediatric MVC mortality within counties. Adjusted analyses accounted for population age and sex, emergency medical service response times, helicopter ambulance availability, state traffic safety laws, and measures of rurality. During the study period 3,067 children died in fatal crashes. We identified 188 pediatric trauma centers in 141 counties. Significant disparities in access to pediatric trauma care were observed. Specifically, 99% of pediatric trauma centers were situated in population-dense urban counties, while 28% of children lived in counties no trauma center. After risk adjustment, counties with pediatric trauma centers had significantly lower rates of pediatric MVC death than those with no trauma center: 0.7 versus 3.2 deaths/100,000 child-years; mortality rate ratio, 0.58; and 95% confidence interval, 0.39 to 0.86. In counties where pediatric trauma centers were absent, adult level 1/2 trauma centers were associated with comparable risk reduction. The presence of pediatric trauma centers was associated with lower rates of MVC death in children. Adult level 1/2 trauma centers appear to offer comparable risk reduction. Where population differences in pediatric trauma mortality are observed, addressing disparities in county-level access to pediatric trauma care may serve as a viable target for system-level improvement. Epidemiological, level III; Care management, level III.

Biomechanical Response Targets of Adult Human Ribs in Frontal Impacts.

Thorax injuries mainly due to rib fractures have been associated with high rates of morbidity and mortality in motor vehicle crashes. Thoracic biomechanics has been studied extensively, but there are no robust biomechanical response targets for ribs that consider age, sex, body size, and vulnerability factors. The objective of this study was to generate biomechanical targets for human rib response with respect to age, sex, and body size. Two-hundred sixty-one ribs from 171 individuals were dynamically loaded to failure in anterior-posterior bending. Force and displacement at the time of fracture in young adults were greater than in older adults (p < 0.0001). Sex differences were found in those over 40years old (p < 0.0001). Fracture force from 5th percentile female ribs was lower than 50th and 95th male (p < 0.005). Vulnerable ribs were successfully identified by examining the percentile of both force and displacement at the time of fracture in the proposed samples. The biomechanical targets generated in this study will have useful applications to computational thorax and rib models to aid in injury prevention measures.

The impact of state laws on motor vehicle fatality rates, 1999-2015.

Motor vehicle crash (MVC) fatalities have been declining while states passed various legislation targeting driver behaviors. This study assesses the impact of state laws on MVC fatality rates to determine which laws were effective. Publically available data were collected on driver-related motor vehicle laws, law strengths, enactment years, and numbers of verified-trauma centers. Prospective data on crash characteristics and MVC fatalities 16 years or older from Fatality Analysis Reporting System 1999 to 2015 (n = 850) were obtained. Generalize Linear Autoregressive Modeling was used to assess the relative contribution of state laws to the crude MVC fatality rate while controlling for other factors. Lowering the minimum blood alcohol content (BAC) was associated with largest declines for all ages, especially the older cohorts: 16 years to 20 years (B = 0.23; p < 0.001), 21 years to 55 years (B = 1.7; p < 0.001); 56 years to 65 years (B = 3.2; p < 0.001); older than 65 years (B = 4.1; p < 0.001). Other driving under the influence laws were also significant. Per se BAC laws accompanying a reduced BAC further contributed to declines in crude fatality rates: 21 years to 55 years (B = -0.13; p < 0.001); older than 65 years (B = -0.17; p < 0.05). Driving under the influence laws enhancing the penalties, making revocation automatic, or targeting social hosts had mixed effects by age. Increased enforcement, mandatory education, vehicle impoundment, interlock devices, and underage alcohol laws showed no association with declining mortality rates. Red light camera and seatbelt laws were associated with declines in mortality rates for all ages except for older than 65 years cohort, but speed camera laws had no effect. Graduated Driver License laws were associated with declines for 16 years to 21 years (B = -0.06; p < 0.001) only. Laws targeting specific risks (elderly, motorcycles, marijuana) showed no effect on declining MVC mortality rates during the study period. States have passed a wide variety of laws with varying effectiveness. A few key laws, specifically laws lowering allowable BAC, implementing red light cameras, and mandating seatbelt use significantly reduced MVC mortality rates from 1999 to 2015. Simply adding more laws/penalties may not equate directly to lives saved. Continued research on state laws will better inform policy makers to meet evolving public health needs in the management of MVC fatalities. Epidemiological, Level III.

Pediatric road traffic injuries in Qatar: Evidence for a developmental stage approach to road safety.

Road traffic injuries are the leading cause of death in Qatar but their epidemiology in children has not been fully described. This paper will describe the epidemiology of pediatric road traffic injuries (pRTIs) in Qatar, in order to understand the relationships among risk factors, mechanisms of injury, use of safety equipment, and according to child developmental stages.The primary sample for this study was drawn from all pRTIs (0–18 years) from January 2010 to December 2012—motor vehicle occupants, passengers and drivers, pedestrians, cyclists, motorcyclists, and all-terrain vehicle (ATV) drivers and passengers—seen at the trauma registry of the Hamad Trauma Center, the national Level I Trauma Referral Center of Qatar.During those two years, the Trauma Center attended to 4864 patients, 443 (9.1%) of whom were pRTIs, 83% were male, and 71% were non-Qatari. Only 1.2% of injured passengers and drivers were restrained. All fatalities were passengers or drivers; the overall mortality rate was 3.4%. The motor vehicle crash (MVC) mortality rate was 6.2%, with the longest mean length of hospital stay 10.5 days and highest Intensive Care Unit (ICU) admission rate 35.7%. Older adolescents (15–18 years) comprised 56.4% of total MVC mortality. One-in-four (25%) pedestrian victims was Qatari. They had the lowest mean Injury Severity Score (9.6); 73% were nine years or younger. ATV victims had a 27% ICU admission rate; 48.4% were 10–14 years old. Older adolescents made up only 17% of the pediatric population of Qatar, yet 40% of pRTI victims and 80% of pRTI deaths. Forty-two percent of injured older adolescents were drivers, with half (21%) of those underage.There are clear and distinct age and mechanism-specific patterns of pRTIs among children in Qatar that must be used to guide road safety policy and program formulation for underage pedestrians and drivers. Proven interventions that increase seatbelt and child restraint use and graduated driver licensing must be considered.

Evaluation of Pedestrian/Bicycle Crash Injury Case Definitions for Use with NC DETECT

ObjectiveTo evaluate four ICD-10-CM based case definitions designed to capture pedestrian and bicycle crash-related emergency department (ED) visits in North Carolina’s statewide syndromic surveillance system, NC DETECT.IntroductionOver the last few decades, the United States has made considerable progress in decreasing the incidence of motor vehicle occupants injured and killed in traffic collisions.1 However, there is still a need for continued motor vehicle crash (MVC) injury surveillance, particularly for vulnerable road users, such as pedestrians and bicyclists. In NC, the average annual number of pedestrian-motor vehicle crashes increased by 13.5 percent during the period 2011-2015, as compared to 2006-2010.2 Therefore, the Carolina Center for Health Informatics (CCHI), as part of a NC Governor’s Highway Safety Program-funded project to improve statewide MVC injury surveillance, developed and evaluated four ICD-10-CM based case definitions for use with NC DETECT, NC’s statewide syndromic surveillance system.MethodsWe created four pedestrian/bicycle crash injury case definitions based on ICD-10-CM transportation codes (“V-codes”): Traffic-Related Pedestrian Crashes, Traffic/Non-Traffic-Related Pedestrian Crashes, Traffic-Related Bicycle Crashes, and Traffic/Non-Traffic-Related Bicycle Crashes. These definitions were based on the Centers for Disease Control and Prevention (CDC) “ICD-10-CM External Cause of Injury Codes”.3 We then applied these pedestrian/bicycle crash case definitions to 2016-2017 NC DETECT ED visit data and data obtained from a single NC Level I Trauma Center. Next, we linked the two data sources using the variables date of visit, time of visit, and medical record number. Since trauma center data are collected and verified by a designated trauma registrar, we considered the data obtained from the Level I Trauma Center to be the “gold standard”.ResultsThe linkage between the two data sources was successful, with 99.5% of all Level I Trauma Center records linking to ED visits in NC DETECT. However, we found discrepancies in the assignment of codes between the ED visit and Trauma Center data. For example, 47.5% of NC DETECT ED visits that linked to a pedestrian/bicycle crash record in the Trauma Center data, were missing an ICD-10-CM injury mechanism code of any category. Historically, the proportion of injury-related ED visits that were missing corresponding injury mechanism codes was low (&lt;15%). However, the transition from ICD-9-CM to ICD-10-CM increased the proportion of injury-related visits missing injury mechanism codes.4 Among the 92 NC DETECT ED visits missing injury mechanism codes, 35.9% contained a pedestrian/bicycle crash-related keyword in the Chief Complaint or Triage Note.Among the 100 linked records with valid ICD-10-CM injury mechanism codes, the percent agreement between the two data sources on whether the ED visit was a “pedestrian” or “bicycle” crash was 54.4% and 71.9%, respectively. Percent agreement decreased for “traffic” and “non-traffic” designations, however. The most common V-code assigned to misclassified pedestrian/bicycle crashes in the NC DETECT ED visit data was “V87.7XXA-Person injured in a collision between other specified motor vehicles (traffic)”.Although the linkage study used data obtained from only a single Level I Trauma Center and primarily a single facility in NC DETECT, we felt that the results of this limited linkage study were generalizable to statewide NC DETECT ED visit data. For example, many facilities in NC DETECT underreport injury mechanism codes. Therefore, we added pedestrian/bicycle crash injury-related keywords to the Traffic/Non-Traffic Pedestrian/Bicycle Crash Injury case definitions (Table 1). After inclusion of these keywords, the number of identified pedestrian and bicycle crash injury-related ED visits identified in NC DETECT increased by 16.9% and 57.9% from January-June 2018, respectively (Figure 1).ConclusionsPedestrian and bicycle crashes represent a major cause of MVC injury morbidity and mortality. Therefore, the development and evaluation of case definitions is key for the successful surveillance of these types of injuries. The inclusion of keywords can help account for some of the injury mechanism data missingness common to ED surveillance systems.

Association Between Emergency Medical Service Response Time and Motor Vehicle Crash Mortality in the United States

Motor vehicle crashes (MVCs) are a leading public health concern. Emergency medical service (EMS) response time is a modifiable, system-level factor with the potential to influence trauma patient survival. The relationship between EMS response time and MVC mortality is unknown. To measure the association between EMS response times and MVC mortality at the population level across US counties. This population-based study included MVC-related deaths in 2268 US counties, representing an estimated population of 239 464 121 people, from January 1, 2013, through December 31, 2015. Data were analyzed from October 1, 2017, through April 30, 2018. The median EMS response time to MVCs within each county (county response time), derived from data collected by the National Emergency Medical Service Information System. The county rate of MVC-related death, calculated using crash fatality data recorded in the Fatality Analysis Reporting System of the National Highway Traffic Safety Administration. During the study period, 2 214 480 ambulance responses to MVCs were identified (median, 229 responses per county [interquartile range (IQR), 73-697 responses per county]) in 2268 US counties. The median county response time was 9 minutes (IQR, 7-11) minutes. Longer response times were significantly associated with higher rates of MVC mortality (≥12 vs <7 minutes; mortality rate ratio, 1.46; 95% CI, 1.32-1.61) after adjusting for measures of rurality, on-scene and transport times, access to trauma resources, and traffic safety laws. This finding was consistent in both rural/wilderness and urban/suburban settings, where a significant proportion of MVC fatalities (population attributable fraction: rural/wilderness, 9.9%; urban/suburban, 14.1%) were associated with prolonged response times (defined by the median value, ≥10 minutes and ≥7 minutes, respectively). Among 2268 US counties, longer EMS response times were associated with higher rates of MVC mortality. A significant proportion of MVC-related deaths were associated with prolonged response times in both rural/wilderness and urban/suburban settings. These findings suggest that trauma system-level efforts to address regional disparities in MVC mortality should evaluate EMS response times as a potential contributor.

Comparison of US County-Level Public Health Performance Rankings With County Cluster and National Rankings

Health departments can be grouped together based on sociodemographic characteristics of the population served. Comparisons within these groups can then help with monitoring and improving the health of their populations. To compare county-level percentile rankings on outcomes of smoking, motor vehicle crash deaths, and obesity within sociodemographic peer clusters vs nationwide rankings. This cross-sectional, population-based study of demographic and health data from the 2014 Behavioral Risk Factor Surveillance System and the 2016 Robert Wood Johnson Foundation County Health Rankings data set was conducted at 3139 of 3143 US counties and county-equivalents. Four locations were excluded due to incomplete data. Data analysis was conducted between January and August 2017. Random forest algorithms were used to identify sociodemographic characteristics most associated with the outcomes of interest. These characteristics were race and ethnicity, educational attainment, age, marital status, employment status, sex, and health insurance status. k-means clustering was used to cluster counties based on these sociodemographic characteristics and the percentage of the county classified as rural. County-level smoking prevalence, motor vehicle crash death rate, and obesity prevalence. County percentile rankings on the outcomes of interest were compared in the national context and the within-cluster context. A total of 318 856 967 individuals (mean [SD] individuals per county, 101 579.2 [326 315]; 161 911 910 women [50.8%]) were represented by the 3139 counties used in this analysis. Eight distinct sociodemographic clusters throughout the United States were found. Cluster-specific percentile rankings for both smoking prevalence and motor vehicle crash death rates improved more than 70 percentile points for several counties in the rural, American Indian cluster compared with the nationwide percentiles. Conversely, the young, urban, middle to high socioeconomic status cluster included counties with cluster-specific percentile rankings that declined by 60 percentile points or more compared with the nationwide rankings for all 3 outcomes of interest. Comparing county health outcomes on a nationwide or statewide basis fails to adequately account for sociodemographic context. Clustering counties by sociodemographic factors related to the outcome of interest allows a better understanding of other factors that may be shaping the prevalence of health outcomes. These groupings may also aid learning exchange.

Crash Fatality Rates After Recreational Marijuana Legalization in Washington and Colorado.

To evaluate motor vehicle crash fatality rates in the first 2 states with recreational marijuana legalization and compare them with motor vehicle crash fatality rates in similar states without recreational marijuana legalization. We used the US Fatality Analysis Reporting System to determine the annual numbers of motor vehicle crash fatalities between 2009 and 2015 in Washington, Colorado, and 8 control states. We compared year-over-year changes in motor vehicle crash fatality rates (per billion vehicle miles traveled) before and after recreational marijuana legalization with a difference-in-differences approach that controlled for underlying time trends and state-specific population, economic, and traffic characteristics. Pre-recreational marijuana legalization annual changes in motor vehicle crash fatality rates for Washington and Colorado were similar to those for the control states. Post-recreational marijuana legalization changes in motor vehicle crash fatality rates for Washington and Colorado also did not significantly differ from those for the control states (adjusted difference-in-differences coefficient = +0.2 fatalities/billion vehicle miles traveled; 95% confidence interval = -0.4, +0.9). Three years after recreational marijuana legalization, changes in motor vehicle crash fatality rates for Washington and Colorado were not statistically different from those in similar states without recreational marijuana legalization. Future studies over a longer time remain warranted.

Primary Enforcement of Mandatory Seat Belt Laws and Motor Vehicle Crash Deaths

Policies that allow directly citing motorists for seat belt non-use (primary enforcement) have been shown to reduce motor vehicle crash deaths relative to secondary enforcement, but the evidence base is dated and does not account for recent improvements in vehicle designs and road safety. The purpose of this study was to test whether recent upgrades to primary enforcement still reduce motor vehicle crash deaths. In 2016, researchers used motor vehicle crash death data from the Fatal Analysis Reporting System for 2000-2014 and calculated rates using both person- and exposure-based denominators. Researchers used a difference-in-differences design to estimate the effect of primary enforcement on death rates, and estimated negative binomial regression models, controlling for age, substance use involvement, fixed state characteristics, secular trends, state median household income, and other state-level traffic safety policies. Models adjusted only for crash characteristics and state-level covariates models showed a protective effect of primary enforcement (rate ratio, 0.88, 95% CI=0.77, 0.98; rate difference, -1.47 deaths per 100,000 population, 95% CI= -2.75, -0.19). After adjustment for fixed state characteristics and secular trends, there was no evidence of an effect of upgrading from secondary to primary enforcement in the whole population (rate ratio, 0.98, 95% CI=0.92, 1.04; rate difference, -0.22, 95% CI= -0.90, 0.46) or for any age group. Upgrading to primary enforcement no longer appears protective for motor vehicle crash death rates.

Economic development and road traffic fatalities in two neighbouring African nations

IntroductionThe rapid growth of Botswana’s economy since independence in 1966 has brought more tarred roads and vehicles, accompanied by an escalating road crash fatality rate. We tested the hypothesis that motor vehicle crash fatality increases resulted from, rather than just corresponded with, annual gross domestic product (GDP) increases. Data from Zambia, adjacent to Botswana, were used for comparison.MethodsAnnual social and economic indicators and motor vehicle crash fatality rates in Botswana and Zambia were accessed from 1960 to 2012 and analysed using vector autoregressive analysis and Granger causality tests.ResultsIn Botswana, annual changes in per capita GDP predicted annual changes in motor vehicle crash fatality rates (p = 0.042). The opposite was not observed; annual changes in motor vehicle crash fatality rates did not predict annual GDP changes. These findings suggest that GDP growth in a given year caused additional road traffic fatalities in Botswana and that, on average, every billion dollar increase in GDP produced an increase in the rate of road traffic fatalities. In Zambia, annual GDP changes predicted annual fatality rate changes three years later (p = 0.029), but annual changes in road crash fatality rates also predicted annual increases in per capita GDP (p = 0.026) three years later, suggesting a correlation between trends, but not a causal effect of GDP.ConclusionRoad crash fatalities increased in recent decades in both Zambia and Botswana. But the rapid economic development in Botswana over this time period appears to have driven proportionate road traffic fatality increases. There are opportunities for newly emerging economies such as Zambia, Angola, and others to learn from the Botswana experience. Evidence-based investments in road safety interventions should be concomitant with economic development.

Mature Driver Laws and State Predictors of Motor Vehicle Crash Fatality Rates Among the Elderly: A Cross-sectional Ecological Study

Objective: State-level data have indicated that motor vehicle crash (MVC) fatality rates among the elderly vary widely across states. To date, the majority of states have implemented mature driver laws, which often require more frequent license renewals, in-person renewal, and vision testing for drivers above a certain age. We sought to evaluate the impact of mature driver laws on states’ MVC fatality rates among the elderly while examining other state-level determinants of MVC-related deaths.Methods: We performed a cross-sectional ecological study and modeled state MVC fatality rates for the population over age 65 as a function of state transportation policies and demographic, health system, population health, travel, and climate characteristics using a general linear model. Principal component analysis was used to reduce dimensionality of the data and overcome multicollinearity of state predictor variables.Results: Higher average temperature, higher gas prices, and a greater number of emergency medicine physicians to population size were significantly associated with lower MVC fatality rates. Positive predictors of MVC fatality rates were percentage of population overweight or obese and percentage with college degree over the age of 65. Having any restriction on elderly drivers was associated with a higher MVC fatality rate and no individual component of mature driver laws (shortened renewal cycle, in-person renewal, and vision testing) was significantly associated with lower fatality MVC rates for adults over 65.Conclusions: Mature driver laws are not associated with lower state MVC fatality rates among the elderly.

Rear-facing child car seats: are laws requiring them effective?

INTRODUCTION: Motor vehicle crashes are a leading cause of death in children aged ≤ 2 years in the U.S. The American Academy of Pediatrics advised that children should remain in rear-facing child car seats to mitigate injury from the most common type of severe collision (frontal). Several states have passed laws following these recommendations. Methods: In 2013 publicly available statutes and comprehensive motor vehicle fatality data from the National Highway Traffic Safety Administration's Fatality Analysis Reporting System database were used to investigate whether there is a relationship between motor vehicle crash fatality rates for children under 1 year of age and state laws regulating the direction of car seat placement. States with known rear-facing car seat laws in place were analyzed in a two-step approach in 2014. Simple fatality rates per 100 million vehicle miles were calculated with 95% Poisson CIs. A negative binomial count model for infant deaths was calculated, with state fixed effects, adjusted for the exposure of vehicle miles in each state by year. Results: Unadjusted models showed a protective mortality effect for rear-facing car seat laws, while adjusted models demonstrated no beneficial effect. Implications: This preliminary study suggests that state rear-facing child restraint laws may be having an impact on infant motor vehicle mortality; however the current model is unable to determine their relative contribution given the overall decline in traffic mortality. Language: en

Does Obesity Increase the Risk of Injury or Mortality in Motor Vehicle Crashes? A Systematic Review and Meta-Analysis

The objective of this review was to assess the risk of obesity in injuries and fatalities resulting from motor vehicle crash (MVC), as compared with individuals with a normal-range body mass index. A systematic review of the literature was conducted yielding 824 potential studies. Nine of these studies met our inclusion criteria. Meta-analyses examining obesity as a risk factor for various injury types and risk of fatality were conducted using data from these studies. Obesity was associated with higher fatality risk (odds ratio [OR] = 1.89, 95% confidence interval [CI] = 1.51-2.37, P = .0001; pooled estimate from 6 studies), and increased risk of lower extremity fractures (OR = 1.39, 95% CI = 1.18-1.65, P = .0001; pooled estimate from 2 studies). No significant differences were observed when considering abdominal injuries or pelvic fractures. Interestingly, for head injuries obesity was a protective factor (OR = 0.67, 95% CI = 0.46-0.97, P = .0001; pooled data from 3 studies). Evidence strongly supports the association of obesity with higher fatality and fractures of the lower extremities in MVCs. Contrary to our hypothesis, 3 studies showed that obesity was a protective factor in reducing head injuries. Furthermore, the review shows that obesity was not a risk factor of MVC-related pelvic fractures and abdominal injuries.

Defining the “older” crash victim: The relationship between age and serious injury in motor vehicle crashes

Objective Age is often used as a predictor of injury and mortality in motor vehicle crashes (MVCs), however, the age that defines an “older” occupant in terms of injury-risk remains unclear, as do specific injury patterns associated with increasing age. The objective of this study was to evaluate the relationship between age and serious injury (including injury patterns) for occupants involved in MVCs. Methods This was a retrospective cohort study using a national population-based cohort of adult front-seat occupants involved in MVCs and included in the National Automotive Sampling System Crashworthiness Data System database from 1995 to 2006. The primary outcome was serious injury, defined as an abbreviated injury scale (AIS) score ≥3 in any body region. Anatomic injury patterns were also assessed by age. Results One hundred thousand one hundred and fifty-six adult front-seat occupants were included in the analysis, of which 14,128 (2%) were seriously injured. Age was a strong predictor of serious injury using a variety of different age covariates (categorical, continuous, and polynomial) in multivariable regression models ( p < 0.0001 for all). There was evidence of a strong non-linear relationship between age and serious injury ( p < 0.001 for comparison of non-linear to linear representation of age). There was no age that clearly defined an “older” occupant by injury risk, as the odds of injury increased with increasing age across all age groups. The proportion of serious head and extremity injuries gradually increased with increasing age, while serious chest injuries markedly increased after 60 years. Conclusions Age is a strong predictor of serious injury from motor vehicle trauma, the risk of which increases in non-linear fashion as age increases. There is no specific age that clearly defines an “older” occupant by injury risk.