Allison E. Curry

Prevalence of teen driver errors leading to serious motor vehicle crashes

OBJECTIVES Motor vehicle crashes are the leading cause of adolescent deaths. Programs and policies should target the most common and modifiable reasons for crashes. We estimated the frequency of critical reasons for crashes involving teen drivers, and examined in more depth specific teen driver errors. METHODS The National Highway Traffic Safety Administrations (NHTSA) National Motor Vehicle Crash Causation Survey collected data at the scene of a nationally representative sample of 5470 serious crashes between 7/05 and 12/07. NHTSA researchers assigned a single driver, vehicle, or environmental factor as the critical reason for the event immediately leading to each crash. We analyzed crashes involving 15-18 year old drivers. RESULTS 822 teen drivers were involved in 795 serious crashes, representing 335,667 teens in 325,291 crashes. Driver error was by far the most common reason for crashes (95.6%), as opposed to vehicle or environmental factors. Among crashes with a driver error, a teen made the error 79.3% of the time (75.8% of all teen-involved crashes). Recognition errors (e.g., inadequate surveillance, distraction) accounted for 46.3% of all teen errors, followed by decision errors (e.g., following too closely, too fast for conditions) (40.1%) and performance errors (e.g., loss of control) (8.0%). Inadequate surveillance, driving too fast for conditions, and distracted driving together accounted for almost half of all crashes. Aggressive driving behavior, drowsy driving, and physical impairments were less commonly cited as critical reasons. Males and females had similar proportions of broadly classified errors, although females were specifically more likely to make inadequate surveillance errors. CONCLUSIONS Our findings support prioritization of interventions targeting driver distraction and surveillance and hazard awareness training.

Point of Health Care Entry for Youth With Concussion Within a Large Pediatric Care Network

IMPORTANCE Previous epidemiologic research on concussions has primarily been limited to patient populations presenting to sport concussion clinics or to emergency departments (EDs) and to those high school age or older. By examining concussion visits across an entire pediatric health care network, a better estimate of the scope of the problem can be obtained. OBJECTIVE To comprehensively describe point of entry for children with concussion, overall and by relevant factors including age, sex, race/ethnicity, and payor, to quantify where children initially seek care for this injury. DESIGN, SETTING, AND PARTICIPANTS In this descriptive epidemiologic study, data were collected from primary care, specialty care, ED, urgent care, and inpatient settings. The initial concussion-related visit was selected and variation in the initial health care location (primary care, specialty care, ED, or hospital) was examined in relation to relevant variables. All patients aged 0 to 17 years who received their primary care from The Childrens Hospital of Philadelphias (CHOP) network and had 1 or more in-person clinical visits for concussion in the CHOP unified electronic health record (EHR) system (July 1, 2010, to June 30, 2014) were selected. MAIN OUTCOMES AND MEASURES Frequency of initial concussion visits at each type of health care location. Concussion visits in the EHR were defined based on International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes indicative of concussion. RESULTS A total of 8083 patients were included (median age, 13 years; interquartile range, 10-15 years). Overall, 81.9% (95% CI, 81.1%-82.8%; n = 6624) had their first visit at CHOP within primary care, 5.2% (95% CI, 4.7%-5.7%; n = 418) within specialty care, and 11.7% (95% CI, 11.0%-12.4%; n = 947) within the ED. Health care entry varied by age: 52% (191/368) of children aged 0 to 4 years entered CHOP via the ED, whereas more than three-quarters of those aged 5 to 17 years entered via primary care (5-11 years: 1995/2492; 12-14 years: 2415/2820; and 15-17 years: 2056/2403). Insurance status also influenced the pattern of health care use, with more Medicaid patients using the ED for concussion care (478/1290 Medicaid patients [37%] used the ED vs 435/6652 private patients [7%] and 34/141 self-pay patients [24%]). CONCLUSIONS AND RELEVANCE The findings suggest estimates of concussion incidence based solely on ED visits underestimate the burden of injury, highlight the importance of the primary care setting in concussion care management, and demonstrate the potential for EHR systems to advance research in this area.

Adolescent drivers’ perceptions of the advantages and disadvantages of abstention from in-vehicle cell phone use

Driver in-vehicle cell phone use presents a dangerous distraction for adolescent drivers for whom motor vehicle crashes represents the leading cause of death. We used the National Young Driver Survey (NYDS), a nationally representative (N=5665) cross-sectional study of adolescent driving behavior, to examine potential psychosocial correlates of cell phone use while driving (CPWD). Results indicated that stronger beliefs about the advantages of abstention from CPWD were associated with less frequent CPWD, adjusted OR: 0.46 95% [CI: 0.40-0.53]), while stronger beliefs about the disadvantages of abstention were associated with more frequent CPWD, adjusted OR: 1.41 95% CI: [1.21-1.64]. In the absence of strong advantage beliefs, disadvantage beliefs did not have a meaningful association with less frequent CPWD. Almost 30% of adolescents held weaker advantage beliefs coupled with stronger disadvantage beliefs, placing them most at risk. These findings offer guidance for a wide range of intervention and health promotion efforts.

Comparison of teen and adult driver crash scenarios in a nationally representative sample of serious crashes

Motor vehicle crashes are the leading cause of death and acquired disability during the first four decades of life. While teen drivers have the highest crash risk, few studies examine the similarities and differences in teen and adult driver crashes. We aimed to: (1) identify and compare the most frequent crash scenarios-integrated information on a vehicles movement prior to crash, immediate pre-crash event, and crash configuration-for teen and adult drivers involved in serious crashes, and (2) for the most frequent scenarios, explore whether the distribution of driver critical errors differed for teens and adult drivers. We analyzed data from the National Motor Vehicle Crash Causation Survey, a nationally representative study of serious crashes conducted by the U.S. National Highway Traffic Safety Administration from 2005 to 2007. Our sample included 642 16- to 19-year-old and 1167 35- to 54-year-old crash-involved drivers (weighted n=296,482 and 439,356, respectively) who made a critical error that led to their crashs critical pre-crash event (i.e., event that made the crash inevitable). We estimated prevalence ratios (PR) and 95% confidence intervals (CI) to compare the relative frequency of crash scenarios and driver critical errors. The top five crash scenarios among teen drivers, accounting for 37.3% of their crashes, included: (1) going straight, other vehicle stopped, rear end; (2) stopped in traffic lane, turning left at intersection, turn into path of other vehicle; (3) negotiating curve, off right edge of road, right roadside departure; (4) going straight, off right edge of road, right roadside departure; and (5) stopped in lane, turning left at intersection, turn across path of other vehicle. The top five crash scenarios among adult drivers, accounting for 33.9% of their crashes, included the same scenarios as the teen drivers with the exception of scenario (3) and the addition of going straight, crossing over an intersection, and continuing on a straight path. For two scenarios ((1) and (3) above), teens were more likely than adults to make a critical decision error (e.g., traveling too fast for conditions). Our findings indicate that among those who make a driver critical error in a serious crash, there are few differences in the scenarios or critical driver errors for teen and adult drivers.

Long-term changes in crash rates after introduction of a Graduated Driver Licensing decal provision.

BACKGROUND New Jersey (NJ) implemented the first Graduated Driver Licensing (GDL) decal provision in the U.S. in May 2010. An initial study reported a 1-year post-decal decrease in the crash rate among NJ intermediate drivers aged <21 years. Longer-term analysis is critical for policymakers in other states considering whether to implement a decal provision. PURPOSE To evaluate the longer-term (2-year) effect of NJs decal provision on overall and age-specific crash rates of young drivers with intermediate licenses. METHODS Monthly per-driver police-reported crash rates during January 2006-June 2012 were estimated. Specific crash types included injury, midnight-4:59am, single-vehicle, multiple-vehicle, and peer passenger crashes. Negative binomial modeling compared pre- versus post-decal crash rates, adjusting for age, gender, calendar month, gas price, and 21- to 24-year-old licensed driver crash rates; piecewise negative binomial regression models accounted for pre-decal crash trends among intermediate drivers. Analyses were conducted in 2013. RESULTS The adjusted crash rate for intermediate drivers was 9.5% lower in the 2-year post-decal period than the 4-year pre-decal period (95% CI=0.88, 0.93). Crash rates decreased 1.8% per year before the provision and 7.9% per year in the post-decal period (p<0.001 for difference in slopes). For several crash types, effects appeared to be particularly strong for 18- and 19-year-olds. An estimated 3,197 intermediate drivers had crashes prevented. CONCLUSIONS NJs decal provision was associated with a sustained decline in intermediate driver crashes. Future research should aim to better understand the causal mechanism by which NJs decal provision may have exerted an effect.

Statistical implications of using moving violations to determine crash responsibility in young driver crashes

Traditional methods for determining crash responsibility - most commonly moving violation citations - may not accurately characterize at-fault status among crash-involved drivers given that: (1) issuance may vary by factors that are independent of fault (e.g., driver age, gender), and (2) these methods do not capture driver behaviors that are not illegal but still indicative of fault. We examined the statistical implications of using moving violations to determine crash responsibility in young driver crashes by comparing it with a method based on crash-contributing driver actions. We selected all drivers in police-reported passenger-vehicle crashes (2010-2011) that involved a New Jersey driver <21 years old (79,485 drivers<age 21, 61,355 drivers ≥age 21). For each driver, crash responsibility was determined from the crash report using two alternative methods: (1) issuance of a moving violation citation; and (2) presence of a driver action (e.g., failure to yield, inattention). Overall, 18% of crash-involved drivers were issued a moving violation while 50% had a driver action. Only 32.2% of drivers with a driver action were cited for a moving violation. Further, the likelihood of being cited given the presence of a driver action was higher among certain driver subgroups-younger drivers, male drivers, and drivers in single-vehicle and more severe crashes. Specifically among young drivers, those driving at night, carrying peer passengers, and having a suspended or no license were more often cited. Conversely, fatally-injured drivers were almost never cited. We also demonstrated that using citation data may lead to statistical bias in the characterization of at-fault drivers and of quasi-induced exposure measures. Studies seeking to accurately determine crash responsibility should thoughtfully consider the potential sources of bias that may result from using legal culpability methods. For many studies, determining driver responsibility via the identification of driver actions may yield more accurate characterizations of at-fault drivers.

Variation in Teen Driver Education by State Requirements and Sociodemographics

OBJECTIVES: There is renewed attention on national standardization of formal driver education (DE) instruction and momentum toward realigning DE with its original goal of producing safer teen drivers. However, teen DE participation rates and how they differ among sociodemographic groups and in states with and without DE requirements remain largely unknown. Thus, our objective was to estimate national teen participation rates in formal classroom and behind-the-wheel DE instruction in relevant demographic subgroups and also estimate subgroup-specific participation rates by presence of a state DE requirement. METHODS: Data were collected via the National Young Driver Survey, administered to a nationally representative sample of 5665 public school 9th- through 11th-graders in Spring 2006. Analyses were restricted to 1770 students with driver licenses. Survey data were weighted to reflect national prevalence estimates. RESULTS: Overall, 78.8% of students reported participating in formal DE. However, in states without DE requirements, more than 1 in 3 students had no formal DE before licensure, and more than half had no behind-the-wheel training. Hispanics, blacks, males, and students with lower academic achievement participated in DE at markedly lower levels than counterparts in states with requirements. Notably, 71% of Hispanic students in states with no requirement received a license without receiving formal DE. CONCLUSIONS: Considerable racial/ethnic, socioeconomic, and gender disparities in DE participation may exist in states with no DE requirements. State DE requirements may be an effective strategy to reduce these disparities.

Motor Vehicle Crash Risk Among Adolescents and Young Adults With Attention-Deficit/Hyperactivity Disorder

Importance Attention-deficit/hyperactivity disorder (ADHD) often persists into adolescence, when motor vehicle crash risk peaks. We know little about when adolescents with ADHD get licensed and, once they do, the extent to which they have increased crash risk compared with adolescents without ADHD. Objectives To examine the association between ADHD and both driver licensing and crash involvement and whether it varies by sex, licensing age, and/or being prescribed ADHD medication at licensure. Design, Setting, and Participants This retrospective cohort study was conducted at 6 primary care practices of the Children’s Hospital of Philadelphia, a large pediatric health care network in southeastern Pennsylvania and southern New Jersey. Using electronic health records, we defined a cohort of 2479 adolescents and young adults with ADHD and 15 865 without ADHD who were (1) born from 1987 to 1997; (2) residents of New Jersey and patients at 1 of 6 New Jersey primary care practices at age 12 years or older; and (3) age-eligible to obtain a driver’s license from 2004 through 2014. Electronic health records data were then linked with New Jersey’s statewide driver licensing and crash databases for 2004 through 2014. Main Outcomes and Measures Acquisition of a driver’s license and first involvement as a driver in a police-reported crash. Survival analysis was used to estimate adjusted hazard ratios for licensing and crash outcomes through age 25 years. Results The median age of individuals at the end of the study was 22.2 years (interquartile range, 19.7-24.8). Compared with individuals without ADHD, the licensing probability of individuals with ADHD 6 months after eligibility was 35% lower (for males: adjusted hazard ratio, 0.65; 95% CI, 0.61-0.70; females: adjusted hazard ratio, 0.64; 95% CI, 0.58-0.70). Among individuals with a driver’s license, 764 of 1785 with ADHD (42.8%) and 4715 of 13 221 without ADHD (35.7%) crashed during the study period. The adjusted risk for first crash among licensed drivers with ADHD was 1.36 times higher than for those without ADHD (95% CI, 1.25-1.48) and did not vary by sex, licensing age, or over time. Only 129 individuals with ADHD (12.1%) were prescribed medication in the 30 days before licensure. Conclusions and Relevance Adolescents with ADHD get licensed less often and at an older age. Once licensed, this cohort has a greater risk of crashing. Additional research is needed to understand the specific mechanisms by which ADHD influences crash risk.

Young driver licensing: Examination of population-level rates using New Jersey’s state licensing database

Recent surveys have provided insight on the primary reasons why US teens delay licensure but are limited in their ability to estimate licensing rates and trends. State administrative licensing data are the ideal source to provide this information but have not yet been analyzed for this purpose. Our objective was to analyze New Jerseys (NJ) licensing database to: (1) describe population-based rates of licensure among 17- to 20-year-olds, overall and by gender and zip code level indicators of household income, population density, and race/ethnicity; and (2) examine recent trends in licensure. We obtained records on all licensed NJ drivers through June 2012 from the NJ Motor Vehicle Commissions licensing database and determined each young drivers age at the time of intermediate and full licensure. Data from the US Census and American Community Survey were used to estimate a fixed cohort of NJ residents who turned 17 years old in 2006-2007 (n=255,833). Licensing data were used to estimate the number of these drivers who obtained an intermediate license by each month of age (numerators) and, among those who obtained an intermediate license, time to graduation to full licensure. Overall, 40% of NJ residents-and half of those who ultimately obtained a license by age 21-were licensed within a month of NJs minimum licensing age of 17, 64% by their 18th birthday, and 81% by their 21st birthday. Starkly different patterns of licensure were observed by socioeconomic indicators; for example, 65% of 17-year-olds residing in the highest-income zip codes were licensed in the first month of eligibility compared with 13% of residents living in the lowest-income zip codes. The younger an individual obtained their intermediate license, the earlier they graduated to a full license. Finally, the rate and timing of licensure in NJ has been relatively stable from 2006 to 2012, with at most a 1-3% point decline in rates. These findings support the growing body of literature suggesting that teens delay licensure primarily for economic reasons and that a substantial proportion of potentially high-risk teens may be obtaining licenses outside the auspices of a graduated driver licensing system. Finally, our finding of a relatively stable trend in licensure in recent years is in contrast to national-level reports of a substantial decline in licensure rates.

Driving errors of learner teens: Frequency, nature and their association with practice

BACKGROUND Despite demonstrating basic vehicle operations skills sufficient to pass a state licensing test, novice teen drivers demonstrate several deficits in tactical driving skills during the first several months of independent driving. Improving our knowledge of the types of errors made by teen permit holders early in the learning process would assist in the development of novel approaches to driver training and resources for parent supervision. METHODS The purpose of the current analysis was to describe driving performance errors made by teens during the permit period, and to determine if there were differences in the frequency and type of errors made by teens: (1) in comparison to licensed, safe, and experienced adult drivers; (2) by teen and parent-supervisor characteristics; and (3) by teen-reported quantity of practice driving. Data for this analysis were combined from two studies: (1) the control group of teens in a randomized clinical trial evaluating an intervention to improve parent-supervised practice driving (n=89 parent-teen dyads) and (2) a sample of 37 adult drivers (mean age 44.2 years), recruited and screened as an experienced and competent reference standard in a validation study of an on-road driving assessment for teens (tODA). Three measures of performance: drive termination (i.e., the assessment was discontinued for safety reasons), safety-relevant critical errors, and vehicle operation errors were evaluated at the approximate mid-point (12 weeks) and end (24 weeks) of the learner phase. Differences in driver performance were compared using the Wilcoxon rank sum test for continuous variables and Pearsons Chi-square test for categorical variables. RESULTS 10.4% of teens had their early assessment terminated for safety reasons and 15.4% had their late assessment terminated, compared to no adults. These teens reported substantially fewer behind the wheel practice hours compared with teens that did not have their assessments terminated: tODAearly (9.0 vs. 20.0, p<0.001) and tODAlate (19.0 vs. 58.3, p<0.001). With respect to critical driving errors, 55% of teens committed a total of 85 critical errors (range of 1-5 errors per driver) on the early tODA; by comparison, only one adult committed a critical error (p<0.001). On the late tODA, 54% of teens committed 67 critical errors (range of 1-8 errors per driver) compared with only one adult (p<0.001). No differences in teen or parent gender, parent/teen relationship type or parent prior experience teaching a teen to drive were observed between teens who committed a critical error on either route and teens that committed no critical errors. A borderline association between median teen-reported practice quantity and critical error commission was observed for the late tODA. The overall median proportion of vehicle operation errors for teens was higher than that of adults on both assessments, though median error proportions were less than 10% for both teens and adults. CONCLUSION In comparison to a group of experienced adult drivers, a substantially higher proportion of learner teens committed safety-relevant critical driving errors at both time points of assessment. These findings, as well as the associations between practice quantity and the driving performance outcomes studied suggest that further research is needed to better understand how teens might effectively learn skills necessary for safe independent driving while they are still under supervised conditions.