Decomposing the association between the amount of exposure and the frequency of self-reported involvement in a road crash

Overestimation of self-reported driving exposure: Results from the SHRP2 Naturalistic Driving Study

OBJECTIVES

The accuracy of self-reported driving exposure has questioned the validity of using self-reported mileage to inform research questions. Studies examining the accuracy of self-reported driving exposure compared to objective measures find low validity, with drivers overestimating and underestimating driving distance. The aims of the current study were to (1) examine the discrepancy between self-reported annual mileage and driving exposure the following year and (2) investigate whether these differences depended on age and annual mileage.

METHODS

Two estimates of drivers' self-reported annual mileage collected during vehicle installation (obtained via prestudy questionnaires) and approximated annual mileage driven (based upon Global Positioning System data) were acquired from 3,323 participants who participated in the Strategic Highway Research Program 2 (SHRP2) Naturalistic Driving Study.

RESULTS

A Wilcoxon signed rank test showed that there was a significant difference between self-reported and annual driving exposure during participation in SHRP 2, with the majority of self-reported responses overestimating annual mileage the following year, irrespective of whether an ordinal or ratio variable was examined. Over 15% of participants provided self-reported responses with over 100% deviation, which were exclusive to participants underestimating annual mileage. Further, deviations in reporting differed between participants who had low, medium, and high exposure, as well as between participants in different age groups.

CONCLUSIONS

These findings indicate that although self-reported annual mileage is heavily relied on for research, such estimates of driving distance may be an overestimate of current or future mileage and can influence the validity of prior research that has utilized estimates of driving exposure.

Driving self-restriction and motor vehicle collision occurrence in glaucoma

PURPOSE

To confirm that subjects with primary open-angle glaucoma (POAG) who avoid driving in high-risk situations are less likely to be involved in motor vehicle collisions (MVCs) than those who do not.

METHODS

This study evaluated 252 consecutive Japanese aged between 40 and 85 years with POAG. All participants were requested to answer a questionnaire on their driving habits, including self-restriction in driving at night, in rain, in fog, on freeways, and lane changing, and history of MVCs. Those who reported restricting their driving in one or more ways constituted the self-restriction group, and those who reported no self-restriction made up the no-restriction group. The prevalence of MVCs and the crash rate (number of MVCs/10,000 km driven) were compared between the two groups. The association between prevalence of MVCs and the number of driving self-restrictions was also evaluated.

RESULTS

The association between driving self-restriction and MVCs was observed among the male subjects, not among the female subjects. Among the male subjects, the prevalence of MVCs was significantly higher in the no-restriction group than in the self-restriction group (no-restriction group, 33/107 = 30.8%; self-restriction group, 9/66 = 13.6%, p = 0.01). The crash rate was also significantly higher in the no-restriction group (no-restriction group, 1.4 ± 0.8; self-restriction group, 0.4 ± 0.3, average ± SE, p = 0.01). No restriction was significantly associated with MVCs (multivariable-adjusted odds ratios, 2.43 [95% confidence interval, 1.03 to 5.73]). The number of driving self-restrictions was also associated with MVCs (multivariable-adjusted odds ratios, 0.41 [95% confidence interval, 0.18 to 0.99], per one increment of self-restriction).

CONCLUSIONS

Driving self-restriction may be associated with a reduced prevalence of MVCs in men with POAG.

Motorcycle riding under the influence of alcohol: results from the SARTRE-4 survey

Riding a motorcycle under the influence of alcohol is a dangerous activity, especially considering the high vulnerability of motorcyclists. The present research investigates the factors that affect the declared frequency of drink-riding among motorcyclists in Europe and explores regional differences. Data were collected from the SARTRE-4 (Social Attitudes to Road Traffic Risk in Europe) survey, which was conducted in 19 countries. A total sample of 4483 motorcyclists was interviewed by using a face-to-face questionnaire. The data were analyzed by means of multilevel ordered logit models. The results revealed significant regional differences (between Northern, Eastern and Southern European countries) in drink-riding frequencies in Europe. In general, declared drinking and riding were positively associated with gender (males), increased exposure, underestimation of risk, friends' behaviour, past accidents and alcohol ticket experience. On the other hand, it was negatively associated with underestimation of the amount of alcohol allowed before driving, and support for more severe penalties.

Individual variability and predictors of driving simulator impairment in patients with obstructive sleep apnea

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is associated with driving impairment and road crashes. However, daytime function varies widely between patients presenting a clinical challenge when assessing crash risk. This study aimed to determine the proportion of patients showing "normal" versus "abnormal" driving simulator performance and examine whether anthropometric, clinical, and neurobehavioral measures predict abnormal driving.

METHODS

Thirty-eight OSA patients performed a 90-min simulated driving task under 3 conditions: normal sleep, restricted sleep (4 h in bed), and normal sleep + alcohol (BAC∼0.05 g/dL). Patients were classified as "resilient" drivers if, under all 3 experimental conditions their mean steering deviation fell within 2 standard deviations of the mean steering deviation of 20 controls driving under baseline normal sleep conditions, or a "vulnerable" driver if mean steering deviation was outside this range in at least one experimental condition. Potentially predictive baseline anthropometric, clinical, neurocognitive, and cortical activation measures were examined.

RESULTS

Of the 38 OSA patients examined, 23 (61%) and 15 (39%) were classified as resilient and vulnerable drivers, respectively. There were no differences in baseline measures between the groups, although the proportion of females was greater and self-reported weekly driving exposure was less among vulnerable drivers (p < 0.05). On univariate analysis gender, weekly driving hours, and auditory event related potential P2 amplitude were weakly associated with group status. Multivariate analysis showed weekly driving hours (OR 0.69, 95%CI, 0.51-0.94, p = 0.02) and P2 amplitude (OR 1.34, 95%CI 1.02-1.76, p = 0.035) independently predicted vulnerable drivers.

CONCLUSIONS

Most OSA patients demonstrated normal simulated driving performance despite exposure to further sleep loss or alcohol. Most baseline measures did not differentiate between resilient and vulnerable drivers, although prior driving experience and cortical function were predictive. Novel measures to assist identification of OSA patients at risk of driving impairment and possibly accidents are needed.

TRIAL REGISTRATION

Data presented in this manuscript was collected as part of a clinical trial "Experimental Investigations of Driving Impairment in Obstructive Sleep Apnea." Trial ID: ACTRN12610000009011, URL: http://www.anzctr.org.au/trial_view.aspx?ID=334979.

Child injury control: trends, themes, and controversies

Injury is a major cause of morbidity and mortality among US children, and an important driver of health status globally. Despite its enormous burden, injury is preventable. Over the last 10 years, significant progress has been made in the reduction of unintentional injury among US children. However, aggregate trends mask important disparities by age group, region, and injury mechanism. Basic and translation research is needed to develop and test prevention strategies to address these new or recalcitrant problems. Motor vehicle occupant injury has fallen to historic lows, but challenges remain in protecting novice drivers and managing the distraction of new technologies. Injury to pedestrians has also declined, but likely as a result of decreased exposure as fewer children walk. This calls for a broader public health perspective to promote activity while enhancing safety. Deaths due to drowning are common and illustrate the difficulty in measuring and promoting appropriate supervision. Environmental modification and use of protective products may be a more appropriate response. Concussion in sport is another challenging issue: public health laws promote identification and appropriate management of concussed athletes, but less progress has been made on primary prevention of these injuries. Unintentional poisoning is on the rise, attributable to misuse of, and overdose with, prescription opioids. Injury deaths to infants are also increasing. This trend is driven in part by better death investigation that classifies more sleep-related deaths as suffocation events. Finally, we examine a sample of cross-cutting themes and controversies in injury control that might be amenable to empiric evaluation.