Motor Vehicle Crash Rates Research Articles

The Teen Driver

For many teenagers, obtaining a driver's license is a rite of passage, conferring the ability to independently travel to school, work, or social events. However, immaturity, inexperience, and risky behavior put newly licensed teen drivers at risk. Motor vehicle crashes are the most common cause of mortality and injury for adolescents and young adults in developed countries. Teen drivers (15-19 years of age) have the highest rate of motor vehicle crashes among all age groups in the United States and contribute disproportionately to traffic fatalities. In addition to the deaths of teen drivers, more than half of 8- to 17-year-old children who die in car crashes are killed as passengers of drivers younger than 20 years of age. This policy statement, in which we update the previous 2006 iteration of this policy statement, is used to reflect new research on the risks faced by teen drivers and offer advice for pediatricians counseling teen drivers and their families.

School start times and teenage driver motor vehicle crashes

IntroductionShifting school start times to 8:30 am or later has been found to improve academic performance and reduce behavior problems. Limited research suggests this may also reduce adolescent driver motor vehicle crashes. A change in the school start time from 7:30 am to 8:45 am for all public high schools in one North Carolina county presented the opportunity to address this question with greater methodologic rigor. MethodWe conducted ARIMA interrupted time-series analyses to examine motor vehicle crash rates of high school age drivers in the intervention county and 3 similar comparison counties with comparable urban-rural population distribution. To focus on crashes most likely to be affected, we limited analysis to crashes involving 16- & 17-year-old drivers occurring on days when school was in session. ResultsIn the intervention county, there was a 14% downward shift in the time-series following the 75 min delay in school start times (p = .076). There was no change approaching statistical significance in any of the other three counties. Further analysis indicated marked, statistically significant shifts in hourly crash rates in the intervention county, reflecting effects of the change in school start time on young driver exposure. Crashes from 7 to 7:59 am decreased sharply (−25%, p = .008), but increased similarly from 8 to 8:59 am (21%, p = .004). Crashes from 2 to 2:59 pm declined dramatically (−48%, p = .000), then increased to a lesser degree from 3 to 3:59 pm (32%, p = .024) and non-significantly from 4 to 4:59 (19%, p = .102). There was no meaningful change in early morning or nighttime crashes, when drowsiness-induced crashes might have been expected to be most common. DiscussionThe small decrease in crashes among high school age drivers following the shift in school start time is consistent with the findings of other studies of teen driver crashes and school start times. All these studies, including the present one, have limitations, but the similar findings suggest that crashes and school start times are indeed related, with earlier start times equating to more crashes. ConclusionLater high school start times (>8:30 am) appear to be associated with lower adolescent driver crash rates, but additional research is needed to confirm this and to identify the mechanism by which this occurs (reduced drowsiness or reduced exposure).

Adolescent motor vehicle crash prevention through a trauma center-based intervention program.

Therapy, level IV.

Ambulance Crash in a Rural Area of Thailand

BackgroundAmbulance crashes delay patient transfer and endanger patients, ambulance crews, and other road users. In low- and middle-income countries, where motor vehicle crash rates are typically high, ambulances have a high risk of being involved in a crash. This case report describes an ambulance crash in Thailand to elucidate modifiable problems in current protocols and practices of emergency medical services. Case ReportIn November 2016, a 28-year-old male driver of an ambulance died in a crash while transferring a female patient with dizziness to a rural hospital. The driver and another ambulance crew member were sitting in the front seats unrestrained. The other occupants were in the patient compartment unrestrained. The driver was driving the ambulance within the speed limit. He made a sharp turn trying to evade a dog, and the ambulance crashed head-on into a roadside tree. The cabin sustained severe damage, and the occupants in the patient compartment were struck against the compartment wall and were struck by unsecured equipment and the stretcher. The driver sustained a severe brain injury. The other occupants, including the female patient, sustained minor injuries. Why Should an Emergency Physician be Aware of This?This case raises safety issues concerning the following aspects of ambulance operations in low- and middle-income countries: speed limit, safety device use, seatbelt use, securing equipment, and vehicle safety standards. Systematic measures to change protocols or even legislation, as well as data collection, are required to address these issues.

Association Between Medication Use for Attention-Deficit/Hyperactivity Disorder and Risk of Motor Vehicle Crashes

Motor vehicle crashes (MVCs) are a major public health problem. Research has demonstrated that individuals with attention-deficit/hyperactivity disorder (ADHD) are more likely to experience MVCs, but the effect of ADHD medication treatment on the risk of MVCs remains unclear. To explore associations between ADHD medication use and risk of MVCs in a large cohort of patients with ADHD. For this study, a US national cohort of patients with ADHD (n = 2 319 450) was identified from commercial health insurance claims between January 1, 2005, and December 31, 2014, and followed up for emergency department visits for MVCs. The study used within-individual analyses to compare the risk of MVCs during months in which patients received ADHD medication with the risk of MVCs during months in which they did not receive ADHD medication. Dispensed prescription of ADHD medications. Emergency department visits for MVCs. Among 2 319 450 patients identified with ADHD, the mean (SD) age was 32.5 (12.8) years, and 51.7% were female. In the within-individual analyses, male patients with ADHD had a 38% (odds ratio, 0.62; 95% CI, 0.56-0.67) lower risk of MVCs in months when receiving ADHD medication compared with months when not receiving medication, and female patients had a 42% (odds ratio, 0.58; 95% CI, 0.53-0.62) lower risk of MVCs in months when receiving ADHD medication. Similar reductions were found across all age groups, across multiple sensitivity analyses, and when considering the long-term association between ADHD medication use and MVCs. Estimates of the population-attributable fraction suggested that up to 22.1% of the MVCs in patients with ADHD could have been avoided if they had received medication during the entire follow-up. Among patients with ADHD, rates of MVCs were lower during periods when they received ADHD medication. Considering the high prevalence of ADHD and its association with MVCs, these findings warrant attention to this prevalent and preventable cause of mortality and morbidity.

The impact of the 2007 graduated driver licensing law in Massachusetts on the rate of citations and licensing in teenage drivers

ObjectiveWe recently demonstrated that the 2007 Massachusetts Graduated Driving Licensing (GDL) law decreased the rate of motor vehicle crashes in teenage drivers. To better understand this decrease, we sought to examine the law's impact on the issuance of driving licenses and traffic citations to teenage drivers. MethodsCitation and license data were obtained from the Massachusetts Department of Transportation. Census data were obtained from the Census Data Center. Two study periods were defined: pre-GDL (2002–2006) and post-GDL (2007–2012). Two populations were defined: the study population (aged 16–17) and the control population (aged 25–29). The rates of licenses per population were compared pre- vs. post-GDL for the study group. The numbers of total, state, and local citations per population were compared pre- vs. post-GDL for both populations. A sensitivity analysis was performed for the rates of citations using licenses issued as a denominator. ResultsWhile licenses per population obtained by the study group decreased over the entire period, there was no change in the rate of decrease per year pre- vs. post-GDL (2.0% vs. 1.4%; p=0.6392). In the study population, total, state, and local citations decreased post-GDL (17.8% vs. 8.1%, p<0.0001; 3.7% vs. 2.2%, p<0.0001; 14.1% vs. 5.8%, p<0.0001, respectively). In the control group, total and state citations did not change (26.7% vs. 23.9%, p=0.3606; 9.2% vs. 10.2%, p=0.3404, respectively), and local citations decreased (17.5% vs. 13.7%, p=0.0389). The rates of decrease per year for total, state, and local citations were significantly greater in the study population compared with control (p<0.0001, p=0.0002, p<0.0001, respectively). ConclusionsThe 2007 GDL law in Massachusetts was associated with fewer traffic citations without a change in the rate of licenses issued to teenagers. These findings suggest that 2007 GDL may be improving driving habits as opposed to motivating teenagers to delay the issuing of licenses.

Randomized, Prospective Study of the Impact of a Sleep Health Program on Firefighter Injury and Disability

Firefighters' schedules include extended shifts and long work weeks which cause sleep deficiency and circadian rhythm disruption. Many firefighters also suffer from undiagnosed sleep disorders, exacerbating fatigue. We tested the hypothesis that a workplace-based Sleep Health Program (SHP) incorporating sleep health education and sleep disorders screening would improve firefighter health and safety compared to standard practice. Prospective station-level randomized, field-based intervention. US fire department. 1189 firefighters. Sleep health education, questionnaire-based sleep disorders screening, and sleep clinic referrals for respondents who screened positive for a sleep disorder. Firefighters were randomized by station. Using departmental records, in an intention-to-treat analysis, firefighters assigned to intervention stations which participated in education sessions and had the opportunity to complete sleep disorders screening reported 46% fewer disability days than those assigned to control stations (1.4 ± 5.9 vs. 2.6 ± 8.5 days/firefighter, respectively; p = .003). There were no significant differences in departmental injury or motor vehicle crash rates between the groups. In post hoc analysis accounting for intervention exposure, firefighters who attended education sessions were 24% less likely to file at least one injury report during the study than those who did not attend, regardless of randomization (OR [95% CI] 0.76 [0.60, 0.98]; χ2 = 4.56; p = .033). There were no significant changes pre- versus post-study in self-reported sleep or sleepiness in those who participated in the intervention. A firefighter workplace-based SHP providing sleep health education and sleep disorders screening opportunity can reduce injuries and work loss due to disability in firefighters.

The Association between Regional Environmental Factors and Road Trauma Rates: A Geospatial Analysis of 10 Years of Road Traffic Crashes in British Columbia, Canada.

BackgroundBritish Columbia, Canada is a geographically large jurisdiction with varied environmental and socio-cultural contexts. This cross-sectional study examined variation in motor vehicle crash rates across 100 police patrols to investigate the association of crashes with key explanatory factors.MethodsEleven crash outcomes (total crashes, injury crashes, fatal crashes, speed related fatal crashes, total fatalities, single-vehicle night-time crashes, rear-end collisions, and collisions involving heavy vehicles, pedestrians, cyclists, or motorcyclists) were identified from police collision reports and insurance claims and mapped to police patrols. Six potential explanatory factors (intensity of traffic law enforcement, speed limits, climate, remoteness, socio-economic factors, and alcohol consumption) were also mapped to police patrols. We then studied the association between crashes and explanatory factors using negative binomial models with crash count per patrol as the response variable and explanatory factors as covariates.ResultsBetween 2003 and 2012 there were 1,434,239 insurance claim collisions, 386,326 police reported crashes, and 3,404 fatal crashes. Across police patrols, there was marked variation in per capita crash rate and in potential explanatory factors. Several factors were associated with crash rates. Percent roads with speed limits ≤ 60 km/hr was positively associated with total crashes, injury crashes, rear end collisions, and collisions involving pedestrians, cyclists, and heavy vehicles; and negatively associated with single vehicle night-time crashes, fatal crashes, fatal speeding crashes, and total fatalities. Higher winter temperature was associated with lower rates of overall collisions, single vehicle night-time collisions, collisions involving heavy vehicles, and total fatalities. Lower socio-economic status was associated with higher rates of injury collisions, pedestrian collisions, fatal speeding collisions, and fatal collisions. Regions with dedicated traffic officers had fewer fatal crashes and fewer fatal speed related crashes but more rear end crashes and more crashes involving cyclists or pedestrians. The number of traffic citations per 1000 drivers was positively associated with total crashes, fatal crashes, total fatalities, fatal speeding crashes, injury crashes, single vehicle night-time crashes, and heavy vehicle crashes. Possible explanations for these associations are discussed.ConclusionsThere is wide variation in per capita rates of motor vehicle crashes across BC police patrols. Some variation is explained by factors such as climate, road type, remoteness, socioeconomic variables, and enforcement intensity. The ability of explanatory factors to predict crash rates would be improved if considered with local traffic volume by all travel modes.

Syncope and Motor Vehicle Crash Risk: A Danish Nationwide Study.

Syncope may have serious consequences for traffic safety. Current clinical guideline recommendations on driving following syncope are primarily based on expert consensus. To identify whether there is excess risk of motor vehicle crashes among patients with syncope compared with the general population. Danish nationwide cohort study from January 1, 2008, to December 31, 2012. Through individual-level linkage of nationwide administrative registers, all Danish residents 18 years or older were identified. Of 4 265 301 eligible Danish residents, we identified 41 039 individuals with a first-time diagnosis of syncope from emergency department or hospital. Rate of motor vehicle crashes (including nonfatal and fatal crashes), based on multivariate Poisson regression models, using the total Danish population as reference. The 41 039 patients with syncope had a median age of 66 years (interquartile range [IQR], 47-78 years); 51.0% were women; and 34.8% had cardiovascular disease. Through a median follow-up of 2.0 years (IQR, 0.8-3.3 years), 1791 patients with syncope (4.4%) had a motor vehicle crash, 78.1% of which led to injury (n = 1398) and 0.3% to death (n = 6). The crude incidence rate of motor vehicle crashes was almost doubled among patients with syncope (20.6 per 1000 person-years; 95% CI, 19.7-21.6) compared with the general population (12.1; 95% CI, 12.0-12.1), with a rate ratio (RR) of 1.83 (95% CI, 1.74-1.91) after adjustment for age, sex, socioeconomic position, and relevant comorbidities and pharmacotherapy. Men had a relatively higher rate of motor vehicle crashes (RR, 1.91; 95% CI, 1.79-2.03) than women (RR, 1.74; 95% CI, 1.63-1.87). The excess risk of motor vehicle crashes persisted throughout the follow-up period. The 5-year crash risk following syncope was 8.2% (95% CI, 7.5%-8.8%) among the population aged 18 to 69 years compared with 5.1% (95% CI, 4.7%-5.4%) in the general population. Prior hospitalization for syncope was associated with increased risk of motor vehicle crashes throughout the follow-up period. This study suggests that syncope should be considered as one of several factors in a broad assessment of fitness to drive.

A Review of Hazard Anticipation Training Programs for Young Drivers

PurposePoor hazard anticipation skills are a risk factor associated with high motor vehicle crash rates of young drivers. A number of programs have been developed to improve these skills. The purpose of this review was to assess the empirical literature on hazard anticipation training for young drivers. MethodsStudies were included if they (1) included an assessment of hazard anticipation training outcomes; (2) were published between January 1, 1980 and December 31, 2013 in an English language peer-reviewed journal or conference proceeding; and (3) included at least one group that uniquely comprised a cohort of participants aged <21 years. Nineteen studies met inclusion criteria. ResultsStudies used a variety of training methods including interactive computer programs, videos, simulation, commentary driving, or a combination of approaches. Training effects were predominantly measured through computer-based testing and driving simulation with eye tracking. Four studies included an on-road evaluation. Most studies evaluated short-term outcomes (immediate or few days). In all studies, young drivers showed improvement in selected hazard anticipation outcomes but none investigated crash effects. ConclusionsAlthough there is promise in existing programs, future research should include long-term follow-up, evaluate crash outcomes, and assess the optimal timing of hazard anticipation training taking into account the age and experience level of young drivers.

Distracted Driving in Teens With and Without Attention-Deficit/Hyperactivity Disorder

This study is among the first to examine the effect of talking on a cell phone or text messaging while driving in teens with and without attention deficit/hyperactivity disorder (ADHD). Teens (average age 17years) with a diagnosis of ADHD (N=16) were matched with typically developing controls (N=18). All participants operated a driving simulator while (1) conversing on a cell phone, (2) text messaging, and (3) with no distraction during a baseline condition. Six indicators of driving performance were recorded: (a) time to complete the drive; (b) lane deviations; (c) variability in lane position (i.e., root mean square [RMS]); (d) reaction time; (e) motor vehicle collisions; and, (f) speed fluctuation. Significantly greater variation in lane position occurred in the texting task compared to no task and the cell phone task. While texting, in particular, teens with ADHD took significantly less time to complete the scenario. No significant main effects of group were found. Generally, those with ADHD did not differ in regard to driving performance, when compared to controls, with the exception of one outcome: time to complete scenario. These findings suggest that distracted driving impairs driving performance of teen drivers, regardless of ADHD status. Texting while driving had the greatest negative impact on driving performance, particularly with regard to variability in lane position (i.e., RMS). This study sheds light on key issues regarding injury prevention, with the intent of providing pediatric care providers with the knowledge to inform teen drivers of risks associated with distracted driving which will ultimately result in reduced rates of motor vehicle crashes and concomitant injuries.

P13 An international comparison of mobile phone subscribership and motor vehicle crash injuries

BackgroundMobile phone use while driving has been associated with a substantially higher likelihood of motor vehicle crash risk and is the focus of numerous traffic safety policies and initiatives worldwide in recent years. Although prior studies have examined the relationship of distracted driving and crash risk using national data, few if any studies have explored cross-national differences in mobile phone use on motor vehicle crash rates. We use longitudinal data for 23 countries to examine the association between rates of mobile phone subscribership and injuries and fatalities on public roadways. MethodsRoad safety data are reported by the Organization for Economic Co-operation and Development (OECD). We examine 23 OECD countries for the 11-year period, 2001–2011. Generalized least squares (GLS) regression is used to examine logged nonfatal injuries and fatalities per 100,000 population with the log number of mobile phone subscribers per 100 people, adjusting for number of motor vehicles (cars, buses, other), percent urban population, unemployment rate, GDP per capita, year and country fixed effects. ResultsFrom 2001 to 2011, countries experienced a 23.3% decline in rates of motor vehicle injuries—decreasing from 394.2 to 302.5 per 100,000 population. However, trends in motor vehicle crash injuries varied across countries. For example, Denmark and France experienced a more than 50% decrease in injury rates since 2001, but rates in Australia increased 4.4%, from 151.6 to 158.3 per 100,000 population. Mobile phone subscribership increased substantially in this period, but rates and growth also varied significantly across countries. For example, in Switzerland, an average of 10 persons per 100 have a mobile phone; this compares to 77.2 in Great Britain. Growth rates in subscribership ranged from 22.3% in Iceland to nearly 200% in Estonia and Turkey in the study period. GLS regression analysis suggests a significant and positive association between rates of mobile phone subscribership and motor vehicle crash injuries. A 10% increase in subscribers per 100 people is predicted to result in an increase of 12.0% (p<.001) and 7.5% (p<.001) in crash injuries and fatalities per 100,000 people, respectively. ConclusionsWe present evidence that increasing rates of mobile phone subscribership may be associated with motor vehicle crash injuries. Distracted driving is a problem worldwide and, thus, more cross-national efforts are needed to identify best practices in policy implementation to help address this problem.

Injury Prevention as an Integral Part of Health System Reform Efforts: Lessons Learned from Recently Enacted Massachusetts Laws

—Injury is the leading cause of mortality in people younger than 44 years of age. Injury prevention laws and policies are not only effective in saving lives at a population level but are also remarkably cost-effective compared to most public health interventions. For example, the implementation of a stricter Massachusetts Graduated Driver Licensing Law in 2007 resulted in a very significant and rapid decrease in the rates of motor vehicle crashes of teenager drivers, saved thousands of lives, and resulted in more than $10 million dollars savings in health care costs over 5 years. We therefore suggest that trauma and injury prevention should be made a priority in any attempt at local, regional, or national health system reform.

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.

Starting the School Day Later Might Mean Lower Teen Crash Rates

According to this study: * Adolescents attending schools in districts with earlier morning start times had higher motor vehicle crash rates than those in schools with later start times. * A secondary analysis showed that teens with earlier start times had more crashes that involved running off the road to the right, an indirect measure of sleepiness.

Epidemiology of pedestrian–MVCs by road type in Cluj, Romania

ObjectivePedestrian–motor vehicle (PMV) crash rates in Romania are among the highest in all of Europe. The purpose of this study was to examine the characteristics of pedestrian–MVCs in Cluj County,...

ABSTRACT 914

Background and aims: Motor vehicle crashes(MVCs) are the most common cause of death in the United States for adolescents. Since 1998, Massachusetts has implemented a Graduated Driver Licensing (GDL) system requiring teenagers to gain experience under conditions of low crash risk before gaining full privileges. Aims: To evaluate the impact of changes to strengthen Massachusetts’ GDL law on MVCs in 16-18 year olds, and to assess whether these effects persist into young adulthood. Methods: Massachusetts MVC rates were analyzed for drivers aged 16-24 years during two time periods: 2002-2006, before the GDL law was strengthened, and 2007(fourth quarter)-2010, after implementation. Piecewise regression was performed to test whether the rate of change in crash rates by quarter was different for the two time periods, after controlling for age and sex of the driver. Results: MVC rates for drivers aged 16-24 declined by 0.5% per quarter prior to implementation of changes to GDL in 2007, with an accelerated drop of 3.7% per quarter after 2007, a difference of 3.5% (p< 0.001). Results: showed a significant difference in hour of crash and age group of driver. For those 16-18, the percentage of crashes occurring between 12-5am dropped from 7.2% before 2007 to 6.3% after 2007 (p<0.001). For 19-24-year olds there was a similar decrease during those hours from 12.1% before 2007 to 11.2% after 2007. Conclusions: Changes to the Massachusetts GDL law in 2007 to enhance driver education, as well as to enact stricter penalties for violations have contributed to a significant decline in crash rates for Massachusetts youth. These effects persist into young adulthood.

Alcohol-impaired motor vehicle crash risk and the location of alcohol purchase

Motor vehicle crashes involving alcohol impairment are among the leading causes of mortality and morbidity in the U.S. In this study, we examine how the probability of driving after a binge-drinking episode varies with the location of consumption and type of alcohol consumed. We also investigate the relationship between the location of alcohol purchase and the number of alcohol-impaired fatal motor vehicle crashes. Using multiple datasets that are representative of the U.S. between 2003 and 2009, we find that binge-drinkers are significantly more likely to drive after consuming alcohol at establishments that sell alcohol for on-premises consumption, e.g., from bars or restaurants, particularly after drinking beer. Further, per capita sales of alcohol for off-premises consumption are unrelated to the rate of alcohol-impaired fatal motor vehicle crashes. When disaggregating alcohol types, per capita sales of beer for off-premises consumption are negatively associated with the rate of alcohol-impaired fatal motor vehicle crashes. In contrast, total per capita sales of alcohol from all establishments (on- and off-premises) are positively related to the rate of alcohol-impaired fatal motor vehicle crashes and the magnitude of this relationship is strongest for beer sales. Thus, policies that shift consumption away from bars and restaurants could lead to a decline in the number of motor vehicle crashes.

Study on Pattern of Unintentional Transportation Injury Cases Reported at Casualty of a Tertiary Health Care Centre

Injury is probably the most under recognized major public health problem India is facing today. Injuries have always been part of human existence and they comprise a critical health problem throughout the world. In spite of safety legislation and attempt to raise public awareness of the injuries, the rate of motor vehicle crashes, fall from height, suicide, drowning, violence etc. still remains high.

Excessive daytime sleepiness increases the risk of motor vehicle crash in obstructive sleep apnea.

(1) To describe the incidence rate of motor vehicle crashes (MVCs) in patients with obstructive sleep apnea (OSA); and (2) to investigate MVC risk factors in OSA patients. A retrospective case-series observational study was conducted using data from the West Australian Sleep Health Study at a tertiary hospital-based sleep clinic. Participants were patients (N = 2,673) referred for assessment of suspected sleep disordered breathing. Questionnaire data were collected including age, sex, years of driving, near-misses and MVCs, sleepiness, and consumption of alcohol and caffeinated drinks. Overnight laboratory-based polysomnography was performed using standard methodology.(1) Poisson univariate and negative binomial multivariable regression models were used to investigate associations between risk factors and MVC and near-miss risk in patients with untreated OSA. In patients with untreated OSA, the crash rate was 0.06 MVC/person-year compared with the general community crash rate of 0.02 MVC/person-year. The rate ratio comparing very sleepy men with normal men was 4.68 (95% CI 3.07, 7.14) for near-misses and 1.27 (95% CI 1.00, 1.61) for crashes, after adjusting for confounders. In women there was a significant association with sleepiness score (p = 0.02) but no dose effect across quartiles. Untreated OSA is associated with an increased risk of near-misses in men and women and an increased risk of MVCs in very sleepy men. There is a strong association between excessive daytime sleepiness and increased report of near-misses. Our data support the observation that it is those patients with increased sleepiness regardless of OSA severity who are most at risk.