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Background: Polypharmacy use among older adults is of increasing concern for driving safety. This study assesses the individual and joint effects of benzodiazepines and prescription opioids on the incidence of hard braking events in older drivers., Methods: Data for this study came from the Longitudinal Research on Aging Drivers project-a multisite, prospective cohort study of 2990 drivers aged 65-79 years at enrollment (2015-2017). Adjusted incidence rate ratios (aIRRs) and 95% confidence intervals (CIs) of hard braking events (defined as maneuvers with deceleration rates ≥0.4 g and commonly known as near-crashes) were estimated through multivariable negative binominal modeling., Results: Of the 2929 drivers studied, 167 (5.7%) were taking benzodiazepines,  163 (5.6%) prescription opioids, and 23 (0.8%) both drugs at baseline. The incidence rates of hard braking events per 1000 miles driven were 1.14 (95% CI 1.10-1.18) for drivers using neither benzodiazepines nor prescription opioids, 1.25 (95% CI 1.07-1.43) for those using benzodiazepines only, 1.55 (95% CI 1.35-1.76) for those using prescription opioids only, and 1.63 (95% CI 1.11-2.16) for those using both medications. Multivariable modeling revealed that the use of prescription opioids was associated with a 19% increased risk of hard braking events (aIRR 1.19, 95% CI 1.03-1.36). There existed a positive interaction between the two drugs on the additive scale but not on the multiplicative scale., Conclusion: Concurrent use of benzodiazepines and prescription opioids by older drivers appears to affect driving safety through increased incidence of hard braking events., (© 2023 The American Geriatrics Society.)

Problems related to unknown or imprecisely measured populations at risk are common in epidemiologic studies of disease frequency. The size of the population at risk is typically conceptualized as a denominator to be used in combination with a count of disease cases (a numerator) to calculate incidence or prevalence. However, the size of the population at risk can take other epidemiologic properties in relation to an exposure of interest and the count outcome, including confounding, modification, and mediation. Using spatial ecological studies of injury incidence as an example, we identify and evaluate five approaches that researchers have used to address "unknown denominator problems": ignoring, controlling for a proxy, approximating, controlling by study design, and measuring the population at risk. We present a case example and recommendations for selecting a solution given the data and the hypothesized relationship between an exposure of interest, a count outcome, and the population at risk., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background and Objectives: Balancing both driver mobility and safety is important for the well-being of older adults. However, research on the association of physical function with these 2 driving outcomes has yielded inconsistent findings. This study examined whether physical functioning of older drivers, as measured by the Short Physical Performance Battery (SPPB), is associated with either driving space or crash involvement., Methods: Using cross-sectional data of active drivers aged 65-79 years from the AAA Longitudinal Research on Aging Drivers (LongROAD) study (n = 2,990), we used multivariate log-binomial and logistic regressions to estimate the associations of the SPPB with either self-reported restricted driving space in the prior 3 months or any crashes in the past year. Interaction with gender was assessed using likelihood ratio tests., Results: After adjustment, older drivers with higher SPPB scores (higher physical functioning) had lower prevalence of restricted driving space (8-10 vs. 0-7, prevalence ratio [PR] = 0.88, 95% confidence interval [CI]: 0.78-0.99; 11-12 vs. 0-7, PR = 0.78, 95% CI: 0.61-0.99). Fair (8-10), but not good (11-12), scores were significantly associated with reduced crash involvement (8-10 vs. 0-7, odds ratio [OR] = 0.71, 95% CI: 0.60-0.84). Gender was not a significant effect modifier., Discussion and Implications: This study provides evidence that higher physical functioning is associated with better driving mobility and safety and that the SPPB may be useful for identifying at-risk drivers. Further research is needed to understand physical functioning's longitudinal effects and the SPPB's role in older driver intervention programs., (© The Author(s) 2019. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Importance: The prevalence of prescription opioids detected in fatally injured drivers has increased markedly in the past 2 decades in the United States. It is unclear whether driver use of prescription opioids plays a role in fatal crash causation., Objective: To assess the association between driver use of prescription opioids and the risk of being culpable of crash initiation in fatal 2-vehicle crashes., Design, Setting, and Participants: This pair-matched study was based on data from the Fatality Analysis Reporting System for drivers involved in fatal 2-vehicle crashes on US public roads between January 1, 1993, and December 31, 2016. Data analysis was conducted from December 8, 2017, to December 7, 2018., Exposures: Testing positive for prescription opioids compared with testing negative, and blood alcohol concentrations (BACs) based on toxicological testing results., Main Outcomes and Measures: Culpability of crash initiation and adjusted odds ratios and 95% CIs., Results: A total of 36 642 drivers involved in 18 321 fatal 2-vehicle crashes were included. The most common driving error leading to fatal 2-vehicle crashes was failure to keep in lane (7535 [41%]). Drivers culpable of initiating the crashes were more likely than their nonculpable counterparts to test positive for prescription opioids (918 [5.0%] vs 549 [3.0%]; P < .001), alcohol (BAC ≥0.01 g/dL, 5258 [28.7%] vs 1815 [9.9%]; P < .001), and both substances (1.0% vs 0.3%, P < .001). The adjusted odds ratio of crash initiation was 2.18 (95% CI, 1.91-2.48) for drivers testing positive for prescription opioids compared with drivers testing negative, and increased with BACs (BAC 0.01-0.07 g/dL: adjusted odds ratio, 1.97; 95% CI, 1.75-2.22; BAC ≥0.08 g/dL: adjusted odds ratio, 8.20; 95% CI, 7.42-9.07; compared with BAC <0.01 g/dL). There was no significant interaction effect on crash initiation between prescription opioid use and alcohol use., Conclusions and Relevance: Driver use of prescription opioids was associated with initiation of 2-vehicle crashes, independent of alcohol use. Clinicians should take into consideration the adverse effect of opioid analgesics on driving safety while prescribing these medications and counseling patients.

Evidence suggests that older driver safety may be improved by good vehicle maintenance, in-vehicle advanced technologies, and proper vehicle adaptations. This study explored the prevalence of several measures of vehicle maintenance and damage among older drivers through inspection of their vehicles. We also investigated the prevalence of in-vehicle technologies and aftermarket adaptations. Vehicle inspections were conducted by trained research staff using an objective, standardized procedure. This procedure, developed by a multidisciplinary team of researchers, was based on a review of inspection checklists used by automobile dealerships and the project team's expertise. The study used baseline data from vehicles of 2988 participants in the multi-site Longitudinal Research on Aging Drivers (LongROAD) study. Among this cohort, vehicles were well maintained, had little damage, and contained a range of advanced technologies but few aftermarket adaptations. Implications of study findings for occupational therapy practice are discussed.

Background: There are approximately 42 million licensed drivers aged 65 years or older in the United States, who face unique age-related risks while driving. While physical activity affects several chronic conditions thought to be associated with motor vehicle crashes (MVCs), it is unclear if increased physical activity leads to fewer MVCs. This study explores whether self-reported vigorous and moderate physical activity is associated with MVCs in the previous year. Methods: Using cross-sectional data from the LongROAD study, a large multisite prospective cohort study of 2990 older adult drivers, we examined variables related to physical activity and performed a multivariate regression analysis to examine the association of physical activity health behaviors with self-reported MVCs. Results: Overall, 41.2% of participants reported vigorous and 69.6% of participants reported moderate exercise at least once per week. Eleven percent of participants reported at least 1 MVC in the previous year. Neither vigorous nor moderate physical activity was significantly associated with self-reported MVCs in the previous year. Select variables that were significantly associated with self-reported MVC included self-reported unsafe driving practices (odds ratio [OR] 1.55, confidence interval [CI] 1.05-2.29), and fall in the past 12 months (OR 1.46, CI 1.14-1.85). Conclusions: We were unable to detect a significant association between self-reported physical activity and MVCs in the past year among this group of older drivers. Use of objective measures of activity may better clarify this relationship.

Background: The Fatality Analysis Reporting System (FARS) provides important data for studying the role of marijuana in motor vehicle crashes. However, marijuana testing data are available for only 34% of drivers in the FARS, which represents a major barrier in the use of the data., Methods: We developed a multiple imputation (MI) procedure for estimating marijuana positivity among drivers with missing marijuana test results, using a Bayesian multilevel model that allows a nonlinear association with blood alcohol concentrations (BACs), accounts for correlations among drivers in the same states, and includes both individual-level and state-level covariates. We generated 10 imputations for the missing marijuana-testing data using Markov chain Monte Carlo simulations and estimated positivity rates of marijuana in the nation and each state., Results: Drivers who were at older age, female, using seatbelt at the time of crash, having valid license, or operating median/heavy trucks were less likely to test positive for marijuana. There was a reverse U-shaped association between BACs and positivity of marijuana, with lower positivity when BACs < 0.01 g/dL or ≥0.15 g/dL. The MI data estimated a lower positivity rate of marijuana in the nation and each of the state than the observed data, with a national positivity rate of 11.7% (95% CI: 11.1, 12.4) versus 14.8% using the observed data in 2013., Conclusions: Our MI procedure appears to be a valid approach to addressing missing marijuana data in the FARS and may help strengthen the capacity of the FARS for monitoring the epidemic of drugged driving and understanding the role of marijuana in fatal motor vehicle crashes in the United States., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The purpose of the present study was to gain a better understanding of the types of in-vehicle technologies being used by older drivers as well as older drivers' use, learning, and perceptions of safety related to these technologies among a large cohort of older drivers at multiple sites in the United States. A secondary purpose was to explore the prevalence of aftermarket vehicle adaptations and how older adults go about making adaptations and how they learn to use them. The study utilized baseline questionnaire data from 2990 participants from the Longitudinal Research on Aging Drivers (LongROAD) study. Fifteen in-vehicle technologies and 12 aftermarket vehicle adaptations were investigated. Overall, 57.2% of participants had at least one advanced technology in their primary vehicle. The number of technologies in a vehicle was significantly related to being male, having a higher income, and having a higher education level. The majority of respondents learned to use these technologies on their own, with "figured-it-out-myself" being reported by 25%-75% of respondents across the technologies. Overall, technologies were always used about 43% of the time, with wide variability among the technologies. Across all technologies, nearly 70% of respondents who had these technologies believed that they made them a safer driver. With regard to vehicle adaptations, less than 9% of respondents had at least one vehicle adaptation present, with the number of adaptations per vehicle ranging from 0 to 4. A large majority did not work with a professional to make or learn about the aftermarket vehicle adaptation., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Objectives: Opioid analgesics are a major driver of the ongoing opioid epidemic in the United Sates, accounting for about two thirds of drug overdose fatalities. There are conflicting reports regarding the effects of prescription opioids on driving safety. A meta-analysis was performed to assess the epidemiologic evidence for the association between use of prescription opioids and the risk of motor vehicle crashes., Methods: Studies examining the association between driver prescription opioid use and motor vehicle crash involvement or crash culpability and published in English were identified through a comprehensive search of 15 bibliographic databases. Eligible articles were fully reviewed and summarized. Study quality was assessed using the Newcastle-Ottawa Scale. Overall summary odds ratios (ORs) and 95% confidence intervals (CIs) were estimated through random effects models., Results: Overall, 15 studies were included in the meta-analysis; of them, 10 assessed the association of prescription opioid use with the risk of crash involvement and 5 assessed the association of prescription opioid use with the risk of crash culpability. Reported crude ORs associated with prescription opioid use ranged from 1.15 to 8.19 for the risk of crash involvement and from 0.75 to 2.78 for the risk of crash culpability. Summary ORs based on pooled data were 2.29 (95% CI: 1.51, 3.48) for crash risk and 1.47 (95% CI: 1.01, 2.13) for crash culpability., Conclusions: The existent epidemiologic evidence indicates that use of prescription opioids by drivers is associated with significantly increased risks of crash involvement and crash culpability. Further research is needed to understand the epidemiologic patterns of prescription opioid use in the driver population and the interaction effects between opioids and alcohol on driving safety., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Objectives: To examine associations between falls and subsequent motor vehicle crashes (MVCs), crash-related injuries, driving performance, and driving behavior., Design: Systematic review and metaanalysis., Participants: Observational studies including drivers aged 55 and older or with a mean age of 65 and older., Measurements: Two authors independently extracted study and participant characteristics, exposures, and outcomes and assessed risk of bias. Pooled risk estimates for MVCs and MVC-related injuries were calculated using random-effects models. Other results were synthesized narratively., Results: From 3,286 potentially eligible records, 15 studies (N = 27-17,349 subjects) met inclusion criteria. Risk of bias was low to moderate, except for cross-sectional studies (n = 3), which all had a high potential for bias. A fall history was associated with a significantly greater risk of subsequent MVC (summary risk estimate = 1.40, 95% confidence interval (CI) = 1.20-1.63; I 2  = 28%, N = 5 studies). One study found a significantly greater risk of MVC-related hospitalizations and deaths after a fall (hazard ratio = 3.12, 95% CI = 1.71-5.69). Evidence was inconclusive regarding an association between falls and driving cessation and showed no association between falls and driving performance or behavior., Conclusion: Falls in older adults appear to be a risk marker for subsequent MVCs and MVC-related injury. Given the nature of the evidence, which is limited to observational studies, the identified associations may also result at least partly from confounding or bias. Further research is needed to clarify the mechanisms linking falls to crash risk and to develop effective interventions to ensure driving safety in older adults with a history of falls., (© 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.)

Objectives: To assess the time trends in prescription opioids detected in fatally injured drivers., Methods: We analyzed 1995 to 2015 Fatality Analysis Reporting System data from California, Hawaii, Illinois, New Hampshire, Rhode Island, and West Virginia of toxicological tests for drivers fatally injured within 1 hour of a crash (n = 36 729). We used the Cochran-Armitage test for trend to assess the statistical significance of changes in the prevalence of prescription opioids detected in these drivers over time., Results: The prevalence of prescription opioids detected in fatally injured drivers increased from 1.0% (95% confidence interval [CI] = 0.5, 1.4) in 1995 to 7.2% (95% CI = 5.7, 8.8) in 2015 (Z = -9.04; P < .001). Prescription opioid prevalence was higher in female than in male drivers (4.4% vs 2.9%; P < .001). Of the drivers testing positive for prescription opioids, 30.0% had elevated blood alcohol concentrations (≥ 0.01 g/dL), and 66.9% tested positive for other drugs., Conclusions: The prevalence of prescription opioids detected in fatally injured drivers has increased in the past 2 decades. The need to assess the effect of increased prescription opioid use on traffic safety is urgent.

Purpose: To assess individual and joint effects of alcohol and marijuana on the initiation of fatal two-vehicle crashes., Methods: Data on 14,742 culpable drivers (initiators) and 14,742 nonculpable drivers (noninitiators) involved in the same fatal two-vehicle crashes between 1993 and 2014 were obtained from the Fatality Analysis Reporting System. Multivariable conditional logistic regression models were used to assess the association of driver use of alcohol, marijuana, or both with fatal crash initiation with adjustment for demographic variables., Results: Initiators were significantly more likely than non-initiators to test positive for alcohol (28.3% vs. 9.6%, P < .0001), marijuana (10.4% vs. 6.0%, P < .0001), and both substances (4.4% vs. 1.1%, P < .0001). Relative to drivers testing negative for both alcohol and marijuana, the adjusted odds ratios of fatal crash initiation were 5.37 (95% confidence interval [CI]: 4.88 to 5.92) for those testing positive for alcohol and negative for marijuana, 1.62 (95% CI: 1.43 to 1.84) for those testing positive for marijuana and negative for alcohol, and 6.39 (95% CI: 5.19 to 7.88) for those testing positive for both alcohol and marijuana., Conclusions: Alcohol and marijuana each play a significant role in fatal crash initiation. When used in combination, alcohol and marijuana appear to have a positive interaction effect on the risk of fatal crash initiation on the additive scale., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objectives: To assess the association between medical marijuana laws (MMLs) and the odds of a positive opioid test, an indicator for prior use., Methods: We analyzed 1999-2013 Fatality Analysis Reporting System (FARS) data from 18 states that tested for alcohol and other drugs in at least 80% of drivers who died within 1 hour of crashing (n = 68 394). Within-state and between-state comparisons assessed opioid positivity among drivers crashing in states with an operational MML (i.e., allowances for home cultivation or active dispensaries) versus drivers crashing in states before a future MML was operational., Results: State-specific estimates indicated a reduction in opioid positivity for most states after implementation of an operational MML, although none of these estimates were significant. When we combined states, we observed no significant overall association (odds ratio [OR] = 0.79; 95% confidence interval [CI] = 0.61, 1.03). However, age-stratified analyses indicated a significant reduction in opioid positivity for drivers aged 21 to 40 years (OR = 0.50; 95% CI = 0.37, 0.67; interaction P < .001)., Conclusions: Operational MMLs are associated with reductions in opioid positivity among 21- to 40-year-old fatally injured drivers and may reduce opioid use and overdose.

Purpose: Safe Routes to School (SRTS) was a federally funded transportation program for facilitating physically active commuting to and from school in children through improvements of the built environment. There is evidence that SRTS programs increase walking and bicycling in school-age children, but their impact on pedestrian and bicyclist safety has not been adequately examined. We investigate the impact and effects of the SRTS program on school-age pedestrian and bicyclist injuries in a nationwide sample in the United States., Methods: Data were crash records for school-age children (5-19 years) and adults (30-64 years), in 18 U.S. states for a 16-year period (1995-2010). Multilevel negative binomial models were used to examine the association between SRTS intervention and the risk of pedestrian and bicyclist injury in children aged 5-19 years., Results: SRTS was associated with an approximately 23% reduction (incidence rate ratio = 0.77, 95% confidence interval = 0.65-0.92) in pedestrian/bicyclist injury risk and a 20% reduction in pedestrian/bicyclist fatality risk (incidence rate ratio = 0.80, 95% confidence interval = 0.68-0.94) in school-age children compared to adults aged 30-64 years., Conclusions: Implementation of the SRTS program appears to have contributed to improving traffic safety for school-age children in the United States., Competing Interests: Conflict of Interest. The authors have no conflicts of interest to declare., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Drugged driving is a safety issue of increasing public concern. Using data from the Fatality Analysis Reporting System for 1999-2010, we assessed trends in alcohol and other drugs detected in drivers who were killed within 1 hour of a motor vehicle crash in 6 US states (California, Hawaii, Illinois, New Hampshire, Rhode Island, and West Virginia) that routinely performed toxicological testing on drivers involved in such crashes. Of the 23,591 drivers studied, 39.7% tested positive for alcohol and 24.8% for other drugs. During the study period, the prevalence of positive results for nonalcohol drugs rose from 16.6% in 1999 to 28.3% in 2010 (Z = -10.19, P < 0.0001), whereas the prevalence of positive results for alcohol remained stable. The most commonly detected nonalcohol drug was cannabinol, the prevalence of which increased from 4.2% in 1999 to 12.2% in 2010 (Z = -13.63, P < 0.0001). The increase in the prevalence of nonalcohol drugs was observed in all age groups and both sexes. These results indicate that nonalcohol drugs, particularly marijuana, are increasingly detected in fatally injured drivers.

Drugged driving is a serious safety concern, but its role in motor vehicle crashes has not been adequately studied. Using a case-control design, the authors assessed the association between drug use and fatal crash risk. Cases (n=737) were drivers who were involved in fatal motor vehicle crashes in the continental United States during specific time periods in 2007, and controls (n=7719) were participants of the 2007 National Roadside Survey of Alcohol and Drug Use by Drivers. Overall, 31.9% of the cases and 13.7% of the controls tested positive for at least one non-alcohol drug. The estimated odds ratios of fatal crash involvement associated with specific drug categories were 1.83 [95% confidence interval (CI): 1.39, 2.39] for marijuana, 3.03 (95% CI: 2.00, 4.48) for narcotics, 3.57 (95% CI: 2.63, 4.76) for stimulants, and 4.83 (95% CI: 3.18, 7.21) for depressants. Drivers who tested positive for both alcohol and drugs were at substantially heightened risk relative to those using neither alcohol nor drugs (Odds Ratio=23.24; 95% CI: 17.79, 30.28). These results indicate that drug use is associated with a significantly increased risk of fatal crash involvement, particularly when used in combination with alcohol., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Background: In 2005, the US Congress allocated $612 million for a national Safe Routes to School (SRTS) program to encourage walking and bicycling to schools. We analyzed motor vehicle crash data to assess the effectiveness of SRTS interventions in reducing school-aged pedestrian injury in New York City., Methods: Using geocoded motor vehicle crash data for 168 806 pedestrian injuries in New York City between 2001 and 2010, annual pedestrian injury rates per 10 000 population were calculated for different age groups and for census tracts with and without SRTS interventions during school-travel hours (defined as 7 am to 9 am and 2 pm to 4 pm, Monday through Friday during September through June)., Results: During the study period, the annual rate of pedestrian injury decreased 33% (95% confidence interval [CI]: 30 to 36) among school-aged children (5- to 19-year-olds) and 14% (95% CI: 12 to 16) in other age groups. The annual rate of school-aged pedestrian injury during school-travel hours decreased 44% (95% CI: 17 to 65) from 8.0 injuries per 10 000 population in the preintervention period (2001-2008) to 4.4 injuries per 10 000 population in the postintervention period (2009-2010) in census tracts with SRTS interventions. The rate remained virtually unchanged in census tracts without SRTS interventions (0% [95% CI: -8 to 8])., Conclusions: Implementation of the SRTS program in New York City has contributed to a marked reduction in pedestrian injury in school-aged children.

Objective: Graduated Driver Licensing (GDL) has been implemented in Australia, Canada, New Zealand, USA and Israel. We conducted an exploratory summary of available data to estimate whether GDL effects varied with age., Methods: We searched MEDLINE and other sources from 1991-2011. GDL evaluation studies with crashes resulting in injuries or deaths were eligible. They had to provide age-specific incidence rate ratios with CI or information for calculating these quantities. We included studies from individual states or provinces, but excluded national studies. We examined rates based on person-years, not license-years., Results: Of 1397 papers, 144 were screened by abstract and 47 were reviewed. Twelve studies from 11 US states and one Canadian province were selected for meta-analysis for age 16, eight were selected for age 17, and four for age 18. Adjusted rate ratios were pooled using random effects models. The pooled adjusted rate ratios for the association of GDL presence with crash rates was 0.78 (95% CI 0.72 to 0.84) for age 16 years, 0.94 (95% CI 0.93 to 0.96) for 17 and 1.00 (95% CI 0.95 to 1.04) for 18. The difference between these three rate ratios was statistically significant: p<0.001., Conclusions: GDL policies were associated with a 22% reduction in crash rates among 16-year-old drivers, but only a 6% reduction for 17-year-old drivers. GDL showed no association with crashes among 18-year-old drivers. Because we had few studies to summarise, particularly for older adolescents, our findings should be considered exploratory.

Aim: This study aims to examine the prevalence of alcohol and/or other drugs (AOD) in a large sample of fatally injured drivers., Design: Using data from the Fatality Analysis Reporting System for 2005-09, the authors examined the prevalence of AOD detected in fatally injured drivers in the United States., Setting: Fatal motor vehicle crashes occurring on public roads., Participants: Drivers who died within 1 hour of the crash in 14 states that performed toxicological testing on more than 80% of these drivers., Measurements: The prevalence of AOD and multivariable-adjusted prevalence ratios (aPR)., Findings: Of the 20,150 fatally injured drivers studied, 57.3% tested positive for AOD, including 19.9% being positive for two or more substances. Alcohol was the most commonly detected substance, present in 40.2% of the fatally injured drivers, followed by cannabinols (10.5%), stimulants (9.0%), narcotics (5.7%) and depressants (4.0%). Multivariable analysis revealed that AOD was significantly more prevalent among drivers who died in single-vehicle crashes [aPR 1.69, 95% confidence interval (CI): 1.62-1.76] or night-time crashes (aPR 1.43, 95% CI: 1.39-1.47), or who had a driving-while-intoxicated conviction within the past 3 years (aPR 1.41, 95% CI: 1.35-1.47), and less prevalent among drivers who were 65 years or older (aPR 0.45, 95% CI: 0.42-0.49), Asian (aPR 0.47, 95% CI 0.41-0.53) or female (aPR 0.88, 95% CI: 0.85-0.91) or who were operating a motor carrier (aPR 0.41, 95% CI 0.34-0.48)., Conclusions: More than half of fatally injured drivers in the United States had been using AOD and approximately 20% had been using polydrugs. The prevalence of AOD use varies significantly with driver and crash characteristics., (© 2012 The Authors, Addiction © 2012 Society for the Study of Addiction.)

Changing the built environment is a sound, but often underutilized approach to injury control. The authors reviewed the literature and conducted a meta-analysis to synthesize the evidence on the association of roadway characteristics with risk of pediatric pedestrian injury. To synthesize the data, they converted results to odds ratios based on direct results or abstracted outcomes and used Bayesian meta-analytic approaches by modeling outcomes as the logit of a normally distributed set of outcomes with vague prior distributions for the central measure of effect and its variance. On the basis of 10 studies of roadway features restricted exclusively to pediatric populations, the synthesized effect estimate for the association of roadway characteristics with pedestrian injury risk was 2.5 (95% credible interval: 1.8, 3.2). The probability of a new study showing an association between the built roadway and pediatric pedestrian injury was nearly 100%. The authors concluded that the built environment is directly related to the risk of pedestrian injury. This review and meta-analysis suggests that even modest interventions to the built roadway environment may result in meaningful reductions in the risk of pediatric pedestrian injury.

Since 1996, 16 states and the District of Columbia in the United States have enacted legislation to decriminalize marijuana for medical use. Although marijuana is the most commonly detected nonalcohol drug in drivers, its role in crash causation remains unsettled. To assess the association between marijuana use and crash risk, the authors performed a meta-analysis of 9 epidemiologic studies published in English in the past 2 decades identified through a systematic search of bibliographic databases. Estimated odds ratios relating marijuana use to crash risk reported in these studies ranged from 0.85 to 7.16. Pooled analysis based on the random-effects model yielded a summary odds ratio of 2.66 (95% confidence interval: 2.07, 3.41). Analysis of individual studies indicated that the heightened risk of crash involvement associated with marijuana use persisted after adjustment for confounding variables and that the risk of crash involvement increased in a dose-response fashion with the concentration of 11-nor-9-carboxy-delta-9-tetrahydrocannabinol detected in the urine and the frequency of self-reported marijuana use. The results of this meta-analysis suggest that marijuana use by drivers is associated with a significantly increased risk of being involved in motor vehicle crashes.

Objective: To determine the prevalence of alcohol involvement and impairment in fatal crashes in the USA involving Mexican and Canadian drivers., Methods: Drivers in fatal crashes in the USA were identified during 1998 to 2008 from the Fatality Analysis Reporting System, and the prevalence of alcohol involvement and impairment (defined as blood alcohol concentrations ≥0.01 g/dl and ≥0.08 g/dl, respectively) was compared among drivers licensed in Mexico (n=687), Canada (n=598), and the USA (n=561908)., Results: The prevalence of alcohol involvement was 27% for US drivers, 27% for Mexican drivers, and 11% for Canadian drivers. Alcohol impairment was found in 23% of US drivers, 23% of Mexican drivers, and 8% of Canadian drivers. With adjustment for driver demographic characteristics and survival status and for crash circumstances, the prevalence of alcohol involvement was significantly lower for Canadian drivers (adjusted prevalence ratio (PR) 0.63, 95% CI 0.49 to 0.80) than for US drivers, and was similar between Mexican and US drivers (adjusted PR 0.91, 95% CI 0.81 to 1.02)., Conclusions: Alcohol involvement in fatal motor vehicle crashes in the USA is similarly prevalent in US and Mexican drivers, but is substantially less common in Canadian drivers.

Mandatory alcohol testing programs for motor carrier drivers were implemented in the United States in 1995 and have not been adequately evaluated. Using data from the Fatality Analysis Reporting System during 1982-2006, the authors assessed the effectiveness of mandatory alcohol testing programs in reducing alcohol involvement in fatal motor carrier crashes. The study sample consisted of 69,295 motor carrier drivers and 83,436 non-motor-carrier drivers who were involved in 66,138 fatal multivehicle crashes. Overall, 2.7% of the motor carrier drivers and 19.4% of the non-motor-carrier drivers had positive blood alcohol concentrations. During the study period, the prevalence of alcohol involvement in fatal crashes decreased by 80% among motor carrier drivers and 41% among non-motor-carrier drivers. With adjustment for driver age, sex, history of driving while intoxicated, and survival status, implementation of the mandatory alcohol testing programs was found to be associated with a 23% reduced risk of alcohol involvement in fatal crashes by motor carrier drivers (odds ratio = 0.77, 95% confidence interval: 0.62, 0.94). Results from this study indicate that mandatory alcohol testing programs may have contributed to a significant reduction in alcohol involvement in fatal motor carrier crashes.

Objective: In 2003, New York State implemented an enhanced graduated driving licensing (GDL) program that requires extended supervised driving and a passenger restriction. This study examines its safety benefit in 55 Upstate New York counties., Methods: We analyzed fatal/incapacitating traffic injury data among 16-, 17- and 21-24-year olds for the years 2001 and 2005 using the negative binomial model. To adjust for trends in the traffic injury rate, the relative rate ratio (rRR) of 16- and 17-year olds relative to 21-24-year olds was estimated., Results: GDL implementation was associated with a 31% reduction in the driver injury rate (rRR 0.69, 95% confidence interval (CI) 0.49-0.96), but not with any statistically significant change in the passenger injury rate (rRR 1.19, 95% CI 0.77-1.84), or pedestrian and bicyclist injury rate (rRR 1.53, 95% CI 0.89-2.62) among 16-year olds. Sixteen-year olds experienced a 21% decline in licensure rates between 2001 and 2005. GDL implementation had no appreciable impact on driver injury and licensure rates for 17- and 21-24-year olds., Conclusions: GDL implementation is associated with a significant reduction in licensure and driver injury rate among 16-year olds. GDL implementation does not have a statistically significant impact on passenger, pedestrian, and bicyclist injury rates for 16-year olds.

Objective: To examine the validity of police-reported alcohol data for drivers involved in fatal motor carrier crashes., Material and Methods: We determined the availability of blood alcohol concentration (BAC) and police-reported alcohol data on 157,702 drivers involved in fatal motor carrier crashes between 1982 - 2005 using Fatality Analysis and Reporting System (FARS) data. Drivers were categorized as motor carrier drivers if they operated a vehicle with a gross vehicle weight rating of greater than 26,000 pounds. Otherwise, they were classified as non motor carrier drivers. The sensitivity and specificity of police-reported alcohol involvement were estimated for both driver types., Results: Of the 157,702 drivers, 18% had no alcohol information, 15% had BAC results, 42% had police-reported alcohol data, and 25% had both. Alcohol information varied significantly by driver, crash, and vehicle characteristics. For example, motor carrier drivers were significantly more likely (51%) to have BAC testing results compared to non motor carrier drivers (31%) (p<0.001). The sensitivity of police-reported alcohol involvement for a BAC level>or=0.08 was 83% (95% CI 79%, 86%) for motor carrier drivers and 90% (95% CI 89%, 90%) for non motor carrier drivers. The specificity rates were 96% (95% CI 95%, 96%) and 91% (95% CI 90%, 91%), respectively., Conclusions: The sensitivity and specificity of police-reported alcohol involvement are reasonably high for drivers involved in fatal motor carrier crashes. Further research is needed to determine the extent to which the accuracy of police-reported alcohol involvement may be overestimated because of verification bias., Impact on the Industry: Based on the results of this study, the federal government should continue to work with states to strengthen their strategies to increase chemical testing of all drivers involved in fatal crashes.

Context: Implementation of graduated driver licensing programs is associated with reductions in crash rates of young drivers, but graduated driver licensing programs vary in their components. The impact of programs with different components is unknown., Objective: The purpose of this work was to determine which graduated driver licensing programs are associated with the greatest reductions in fatal motor vehicle crashes involving 16-year-old drivers., Methods: We conducted a retrospective study of all 16-year-old drivers involved in fatal crashes in the United States from 1994 through 2004 using data from the Fatality Analysis Reporting System and the US Census Bureau. We measured incidence rate ratios of fatal motor vehicle crashes involving 16-year-old drivers according to graduated driver licensing programs, adjusted for state and year., Results: Compared with state quarters with no graduated driver licensing program components, reductions of 16% to 21% in fatal crash involvement rates of 16-year-old drivers occurred with programs that included > or = 3-month mandatory waiting period, nighttime driving restriction, and either > or = 30 hours of supervised driving or passenger restriction. Reductions of 18% to 21% occurred in state quarters with programs that included > or = 5 of the 7 components examined. Drivers aged 20 to 24 or 25 to 29 years did not experience significant reductions., Conclusion: Comprehensive graduated driver licensing programs are associated with reductions of approximately 20% in 16-year-old drivers' fatal crash involvement rates. The greatest benefit seems to be associated with programs that include age requirements and > or = 3 months of waiting before the intermediate stage, nighttime driving restriction, and either > or = 30 hours of supervised driving or passenger restriction.

Objectives: This study aimed to assess the impact of the 1997 Arkansas helmet law repeal on motorcycle registrations, crash and fatality risks, and alcohol involvement in motorcycle crashes., Methods: Annual motorcycle registration data for the years 1990 through 2001 were obtained from the Arkansas Department of Finance and Administration. These motorcycle registration data were complemented by the motorcycle crash data from the Arkansas State Police Highway Safety Office and motorcycle fatality data for the state of Arkansas from the Fatality Analysis Reporting System. The impact of the repeal on crash rates, helmet usage, and alcohol involvement was assessed through comparisons of data from before (1993 to 1996) and after (1998 to 2001) the repeal., Results: After the repeal, an increase in motorcycle registrations correlated with a marked rise in the total number of crashes and fatalities; however, fatalities per crash remained virtually the same. The proportion of motorcycle fatalities that were not wearing a helmet increased from 47.0% (47/100) before the repeal to 78.2% (104/133) after the repeal (P = 0.001). The overall percentage of fatal motorcycle crashes involving alcohol use remained unchanged after the repeal (37.6% [29/77] to 38.5% [40/104], P = 0.91), but the percentage of fatal crashes involving drinking nonhelmeted drivers increased from 14.2% (11/77) to 33.6% (35/104) (P = 0.003). Inebriated motorcyclists killed in crashes were overwhelmingly non-helmeted (87.5%, 35/40) after the repeal, up from 37.9% (11/29) before the repeal (P < 0.001)., Conclusions: These findings suggest that the repeal of the mandatory helmet law in Arkansas has had a significant adverse effect on road safety.

Objectives: To estimate the risk to public safety posed by drivers with epilepsy, the authors compared annual totals and disease-specific risk for fatal crashes associated with seizures and other medical conditions. They compared individual risks for fatal crashes due to seizures and other causes of mortality in patients with epilepsy., Methods: The authors analyzed Multiple-Cause of Mortality data files from death certificates provided by the National Center for Health Statistics (NCHS) for the years 1995-97. They analyzed International Classification of Diseases-9 codes for underlying causes of death and other major conditions and determined disease-specific rates of fatal crashes associated with seizures and other medical conditions., Results: An average of 44,027 US drivers died annually as a result of motor vehicle crashes during 1995-97; however, only 86 (0.2%, range 82 to 97) of these deaths were associated with seizures in mortality reports. The incidence rate of fatal crashes for patients with seizures was 2.3 times the rate for patients with cardiovascular and hypertensive diseases and 4.6 times the rate for patients with diabetes. The proportionate mortality ratio for motor vehicle crashes in patients with seizures was low (0.2); most patients with epilepsy died of common cardiovascular and systemic disorders., Conclusion: Fatal driver crashes due to seizures are uncommon. This finding supports the current public policy of permitting patients whose seizures are controlled to drive.

This study addresses of the impacts of emergency vehicle (ambulances, police cars and fire trucks) occupant seating position, restraint use and vehicle response status on injuries and fatalities. Multi-way frequency and ordinal logistic regression analyses were performed on two large national databases, the National Highway Traffic Safety Administration's Fatality Analysis Reporting System (FARS) and the General Estimates System (GES). One model estimated the relative risk ratios for different levels of injury severity to occupants traveling in ambulances. Restrained ambulance occupants involved in a crash were significantly less likely to be killed or seriously injured than unrestrained occupants. Ambulance rear occupants were significantly more likely to be killed than front-seat occupants. Ambulance occupants traveling non-emergency were more likely than occupants traveling emergency to be killed or severely injured. Unrestrained ambulance occupants, occupants riding in the patient compartment and especially unrestrained occupants riding in the patient compartment were at substantially increased risk of injury and death when involved in a crash. A second model incorporated police cars and fire trucks. In the combined ambulance-fire truck-police car model, the likelihood of an occupant fatality for those involved in a crash was higher for routine responses. Relative to police cars and fire trucks, ambulances experienced the highest percentage of fatal crashes where occupants are killed and the highest percentage of crashes where occupants are injured. Lack of restraint use and/or responding with 'lights and siren' characterized the vast majority of fatalities among fire truck occupants. A third model incorporated non-special use van and passenger car occupants, which otherwise replicated the second model. Our findings suggest that ambulance crewmembers riding in the back and firefighters in any seating position, should be restrained whenever feasible. Family members accompanying ambulance patients should ride in the front-seat of the ambulance.

Using multiple national data systems, the roles of fragility (susceptibility to injury) versus excessive crash involvement in the increased fatality risk of older drivers per vehicle-mile of travel (VMT) were estimated. For each age and gender group, deaths per driver involved in a crash (a marker of fragility) and drivers involved in crashes per VMT (a marker of excessive crash involvement) were computed. Compared with drivers ages 30-59, those younger than 20 and those 75 or older both had much higher driver death rates per VMT. The highest death rates per mile driven, 13-fold increases, were observed among drivers age 80 or older, who also had the highest death rates per crash. Fragility began to increase at ages 60-64 and increased steadily with advancing age, accounting for about 60-95% of the excess death rates per VMT in older drivers, depending on age group and gender. Among older drivers, marked excesses in crash involvement did not begin until age 75, but explained no more than about 30-45% of the elevated risk in this group of drivers; excessive crashes explained less of the risk among drivers ages 60-74. In contrast, crash over-involvement was the major factor contributing to the high risk of death among drivers younger than 20, accounting for more than 95% of their elevated death rates per VMT. Although both fragility and crash over-involvement contributed to the excess death rates among older drivers per VMT, fragility appeared to be of over-riding importance. These findings suggest that measures to improve the protection of older vehicle occupants in crashes should be vigorously pursued.

This study selected US drivers aged 55 years or older who were involved in fatal crashes in 1990 and 1995 and explored factors that influenced their fatal crash involvement rate. The fatal crash involvement rate (risk of being involved in a fatal crash) can be thought of as the product of the crash fatality rate (risk of dying given a crash), the crash incidence density (risk of crash), and the exposure prevalence (amount of driving). Fatal crash involvement rates increased with age. The relative contributions of the crash incidence densities and exposure prevalences were greater than that of the crash fatality rates. The decomposition methodology was shown to be a useful method for investigating the potential benefit of crash prevention interventions aimed at different components of the fatal crash involvement rate.