Medical interventions to reduce motor vehicle collisions

Effectiveness of road safety interventions: An evidence and gap map

Background

Road Traffic injuries (RTI) are among the top ten leading causes of death in the world resulting in 1.35 million deaths every year, about 93% of which occur in low- and middle-income countries (LMICs). Despite several global resolutions to reduce traffic injuries, they have continued to grow in many countries. Many high-income countries have successfully reduced RTI by using a public health approach and implementing evidence-based interventions. As many LMICs develop their highway infrastructure, adopting a similar scientific approach towards road safety is crucial. The evidence also needs to be evaluated to assess external validity because measures that have worked in high-income countries may not translate equally well to other contexts. An evidence gap map for RTI is the first step towards understanding what evidence is available, from where, and the key gaps in knowledge.

Objectives

The objective of this evidence gap map (EGM) is to identify existing evidence from all effectiveness studies and systematic reviews related to road safety interventions. In addition, the EGM identifies gaps in evidence where new primary studies and systematic reviews could add value. This will help direct future research and discussions based on systematic evidence towards the approaches and interventions which are most effective in the road safety sector. This could enable the generation of evidence for informing policy at global, regional or national levels.

Search Methods

The EGM includes systematic reviews and impact evaluations assessing the effect of interventions for RTI reported in academic databases, organization websites, and grey literature sources. The studies were searched up to December 2019.

Selection Criteria

The interventions were divided into five broad categories: (a) human factors (e.g., enforcement or road user education), (b) road design, infrastructure and traffic control, (c) legal and institutional framework, (d) post-crash pre-hospital care, and (e) vehicle factors (except car design for occupant protection) and protective devices. Included studies reported two primary outcomes: fatal crashes and non-fatal injury crashes; and four intermediate outcomes: change in use of seat belts, change in use of helmets, change in speed, and change in alcohol/drug use. Studies were excluded if they did not report injury or fatality as one of the outcomes.

Data Collection and Analysis

The EGM is presented in the form of a matrix with two primary dimensions: interventions (rows) and outcomes (columns). Additional dimensions are country income groups, region, quality level for systematic reviews, type of study design used (e.g., case-control), type of road user studied (e.g., pedestrian, cyclists), age groups, and road type. The EGM is available online where the matrix of interventions and outcomes can be filtered by one or more dimensions. The webpage includes a bibliography of the selected studies and titles and abstracts available for preview. Quality appraisal for systematic reviews was conducted using a critical appraisal tool for systematic reviews, AMSTAR 2.

Main Results

The EGM identified 1859 studies of which 322 were systematic reviews, 7 were protocol studies and 1530 were impact evaluations. Some studies included more than one intervention, outcome, study method, or study region. The studies were distributed among intervention categories as: human factors (n = 771), road design, infrastructure and traffic control (n = 661), legal and institutional framework (n = 424), post-crash pre-hospital care (n = 118) and vehicle factors and protective devices (n = 111). Fatal crashes as outcomes were reported in 1414 records and non-fatal injury crashes in 1252 records. Among the four intermediate outcomes, speed was most commonly reported (n = 298) followed by alcohol (n = 206), use of seatbelts (n = 167), and use of helmets (n = 66). Ninety-six percent of the studies were reported from high-income countries (HIC), 4.5% from upper-middle-income countries, and only 1.4% from lower-middle and low-income countries. There were 25 systematic reviews of high quality, 4 of moderate quality, and 293 of low quality.

Authors' Conclusions

The EGM shows that the distribution of available road safety evidence is skewed across the world. A vast majority of the literature is from HICs. In contrast, only a small fraction of the literature reports on the many LMICs that are fast expanding their road infrastructure, experiencing rapid changes in traffic patterns, and witnessing growth in road injuries. This bias in literature explains why many interventions that are of high importance in the context of LMICs remain poorly studied. Besides, many interventions that have been tested only in HICs may not work equally effectively in LMICs. Another important finding was that a large majority of systematic reviews are of low quality. The scarcity of evidence on many important interventions and lack of good quality evidence-synthesis have significant implications for future road safety research and practice in LMICs. The EGM presented here will help identify priority areas for researchers, while directing practitioners and policy makers towards proven interventions.

COVID Vaccine Hesitancy and Long-Term Traffic Risks

BACKGROUND

COVID vaccine hesitancy identifies a discrepancy between personal decisions and public guidelines. We tested whether COVID vaccine hesitancy was associated with the long-term risks of a traffic crash.

METHODS

We conducted a population-based longitudinal cohort analysis of adults by determining COVID vaccination status through linkages to electronic medical records. Traffic crashes requiring emergency medical care were defined by multicenter outcome ascertainment of all hospitals throughout the region over the subsequent year.

RESULTS

We identified 11,598,549 total individuals, of whom 1,210,754 had not received a COVID vaccine. A total of 54,558 were subsequently injured in traffic crashes during the 1-year follow-up interval, equal to a risk of 4704 per million. Those who had not received a COVID vaccine had a 58% higher risk than those who had received a COVID vaccine (6983 vs 4438 per million, P < .001). The increased traffic risks among unvaccinated individuals included diverse subgroups, were accentuated for single-vehicle crashes, extended to fatal outcomes, exceeded the risks associated with sleep apnea, and persisted after adjustment for baseline characteristics. The increased risks were validated in analyses using Artificial Intelligence techniques and generally larger than the risks of other adverse events frequently ascribed to COVID vaccination.

CONCLUSIONS

COVID vaccine hesitancy is associated with significant increased long-term risks of a traffic crash. A greater awareness of traffic risks might encourage patients to take protective actions for personal safety.

Adaptation of a European categorization system for driving-impairing medicines in Iran

OBJECTIVE

Road traffic crashes due to impaired driving are a leading cause of preventable injuries and deaths. The purpose of this study was adaptation of a European categorization system for driving-impairing medicines in Iran.

METHODS

DRUID categorization system was used as a leading model to classify medicines. Medicines that were compatible with DRUID categorization system were identified and classified accordingly. Medicines that were not compatible with DRUID categorization system were assessed in an expert panel in terms of possiblity of classification. Instructions for health care providers and advice for patients were prepared based on the medicine's influence on fitness to drive.

RESULTS

Of the 1255 medicines in Iranian pharmacopeia, 488 medicines were classified in four categories. Among classified medicines 43.85% and 25.41% belonged to Category 0 and Category 1. About 13.94%, 10.04%, and 6.76% pertained to Category 2, Category 3, and Multiple categories respectively. Majority of the medicines with moderate and severe adverse influences on driving fitness belonged to the nervous system medicines (72.65%). Most of the medicines with non-existing or minor adverse influences on driving fitness pertained to cardiovascular medicines (16.56%). Majority of uncategorized medicines belonged to Iranian herbal medicines.

CONCLUSION

The current study disclosed that DRUID categorization system was implementable for most of the commonly prescribed medicines. Experimental studies are needed to determine the influence of uncategorized medicines of Iranian pharmacopeia. Other countries with similar settings can adapt DRUID categorization system until they develop their own model using original studies.

Categorization and labeling systems concerning driving-impairing medicines: A scoping review

OBJECTIVE

Classification systems concerning driving-impairing medicines can help healthcare providers identify medicinal drugs with no or the least impairing effects and inform patients of the potential risks of certain medicines to safe driving. This study aimed to comprehensively assess the characteristics of classifications and labeling systems regarding driving-impairing medicines.

METHODS

Google Scholar and several databases, including PubMed, Scopus, Web of Science, EMBASE, safetylit.org, and TRID were searched to identify the relevant published material. The retrieved material was assessed for eligibility. Data extraction was done to compare the categorization/labeling systems concerning driving-impairing medicines in terms of characteristics such as the number of categories, description of each category, and description of pictograms.

RESULTS

After screening 5,852 records, 20 studies were selected for inclusion in the review. This review identified 22 categorization/labeling systems regarding medicines and driving. Classification systems had different characteristics, but most of them were designed based on the graded categorization system described by Wolschrijn. Initially, categorization systems had seven levels, but later the medicine impacts were summarized into 3 or 4 levels.

CONCLUSIONS

Although different categorization/labeling systems regarding driving-impairing medicines are available, the most effective systems in changing driver's behavior are the simple and understandable ones. Besides, health care providers should consider patient's socio-demographic features when informing them about driving under the influence.

COVID Vaccine Hesitancy and Risk of a Traffic Crash

BACKGROUND

Coronavirus disease (COVID) vaccine hesitancy is a reflection of psychology that might also contribute to traffic safety. We tested whether COVID vaccination was associated with the risks of a traffic crash.

METHODS

We conducted a population-based longitudinal cohort analysis of adults and determined COVID vaccination status through linkages to individual electronic medical records. Traffic crashes requiring emergency medical care were subsequently identified by multicenter outcome ascertainment of all hospitals in the region over a 1-month follow-up interval (178 separate centers).

RESULTS

A total of 11,270,763 individuals were included, of whom 16% had not received a COVID vaccine and 84% had received a COVID vaccine. The cohort accounted for 6682 traffic crashes during follow-up. Unvaccinated individuals accounted for 1682 traffic crashes (25%), equal to a 72% increased relative risk compared with those vaccinated (95% confidence interval, 63-82; P < 0.001). The increased traffic risks among unvaccinated individuals extended to diverse subgroups, was similar to the relative risk associated with sleep apnea, and was equal to a 48% increase after adjustment for age, sex, home location, socioeconomic status, and medical diagnoses (95% confidence interval, 40-57; P < 0.001). The increased risks extended across the spectrum of crash severity, appeared similar for Pfizer, Moderna, or other vaccines, and were validated in supplementary analyses of crossover cases, propensity scores, and additional controls.

CONCLUSIONS

These data suggest that COVID vaccine hesitancy is associated with significant increased risks of a traffic crash. An awareness of these risks might help to encourage more COVID vaccination.

Life-threatening alcohol-related traffic crashes in adverse weather: a double-matched case-control analysis from Canada

IMPORTANCE

Drunk driving is a major cause of death in North America, yet physicians rarely counsel patients on the risks of drinking and driving.

OBJECTIVE

To test whether the risks of a life-threatening alcohol-related traffic crash were further accentuated by adverse weather.

DESIGN

Double matched case-control analysis of hospitalised patients.

SETTING

Canada's largest trauma centre between 1 January 1995 and 1 January 2015.

PARTICIPANTS

Patients hospitalised due to a life-threatening alcohol-related traffic crash.

EXPOSURE

Relative risk of a crash associated with adverse weather estimated by evaluating the weather at the place and time of the crash (cases) compared with the weather at the same place and time a week earlier and a week later (controls).

RESULTS

A total of 2088 patients were included, of whom the majority were drivers injured at night. Adverse weather prevailed among 312 alcohol-related crashes and was significantly more frequent compared with control circumstances. The relative risk of a life-threatening alcohol-related traffic crash was 19% higher during adverse weather compared with normal weather (95% CI: 5 to 35, p=0.006). The absolute increase in risk amounted to 43 additional crashes, extended to diverse groups of patients, applied during night-time and daytime, contributed to about 793 additional patient-days in hospital and was distinct from the risks for drivers who were negative for alcohol.

CONCLUSIONS

Adverse weather was associated with an increased risk of a life-threatening alcohol-related traffic crash. An awareness of this risk might inform warnings to patients about traffic safety and counselling alternatives to drinking and driving.

Examining the association between area level deprivation and vehicle collisions that result in injury

OBJECTIVE

The objective of this study was to examine the association between area level deprivation and vehicle collisions resulting in either property damage or injury.

METHODS

A multilevel observational study was conducted using the 2000 to 2010 Saskatchewan Traffic Accident Information System (TAIS) (n = 72,234) and 2006 Census data at the Dissemination Area level (n = 337) for the city of Saskatoon.

RESULTS

Total area level deprivation was associated with severity of traffic collisions, but the association varied based on time of day and road repair status. Collisions were more likely to result in injury from the most deprived (Q5) versus the least deprived quintile (Q1) at all times of day; the difference was greatest in the evening (OR 1.7, 95% CI 1.3 to 2.3). However, there was no other evidence of a monotonic increase in risk associated with area level deprivation. When there were faded markings or potholes, the odds of a collision involving injury were 2.6 (95% CI 1.5 to 4.4) times greater for the most deprived quintile compared to the least deprived quintile. There were no significant differences in the risk of injury between area level deprivation quintiles when road conditions were good.

CONCLUSION

While the association between area level deprivation and whether vehicle collisions result in injury in Saskatoon varies based on time of day and road repairs, under many circumstances the most deprived areas report more injuries from collisions compared to the least deprived.

Life-threatening motor vehicle crashes in bright sunlight

Bright sunlight may create visual illusions that lead to driver error, including fallible distance judgment from aerial perspective. We tested whether the risk of a life-threatening motor vehicle crash was increased when driving in bright sunlight.This longitudinal, case-only, paired-comparison analysis evaluated patients hospitalized because of a motor vehicle crash between January 1, 1995 and December 31, 2014. The relative risk of a crash associated with bright sunlight was estimated by evaluating the prevailing weather at the time and place of the crash compared with the weather at the same hour and location on control days a week earlier and a week later.The majority of patients (n = 6962) were injured during daylight hours and bright sunlight was the most common weather condition at the time and place of the crash. The risk of a life-threatening crash was 16% higher during bright sunlight than normal weather (95% confidence interval: 9-24, P < 0.001). The increased risk was accentuated in the early afternoon, disappeared at night, extended to patients with different characteristics, involved crashes with diverse features, not apparent with cloudy weather, and contributed to about 5000 additional patient-days in hospital. The increased risk extended to patients with high crash severity as indicated by ambulance involvement, surgical procedures, length of hospital stay, intensive care unit admission, and patient mortality. The increased risk was not easily attributed to differences in alcohol consumption, driving distances, or anomalies of adverse weather.Bright sunlight is associated with an increased risk of a life-threatening motor vehicle crash. An awareness of this risk might inform driver education, trauma staffing, and safety warnings to prevent a life-threatening motor vehicle crash.

LEVEL OF EVIDENCE

Epidemiologic Study, level III.

Motor vehicle crashes during pregnancy and cerebral palsy during infancy: a longitudinal cohort analysis

OBJECTIVES

To assess the incidence of cerebral palsy among children born to mothers who had their pregnancy complicated by a motor vehicle crash.

DESIGN

Retrospective longitudinal cohort analysis of children born from 1 April 2002 to 31 March 2012 in Ontario, Canada.

PARTICIPANTS

Cases defined as pregnancies complicated by a motor vehicle crash and controls as remaining pregnancies with no crash.

MAIN OUTCOME

Subsequent diagnosis of cerebral palsy by age 3 years.

RESULTS

A total of 1 325 660 newborns were analysed, of whom 7933 were involved in a motor vehicle crash during pregnancy. A total of 2328 were subsequently diagnosed with cerebral palsy, equal to an absolute risk of 1.8 per 1000 newborns. For the entire cohort, motor vehicle crashes correlated with a 29% increased risk of subsequent cerebral palsy that was not statistically significant (95% CI -16 to +110, p=0.274). The increased risk was only significant for those with preterm birth who showed an 89% increased risk of subsequent cerebral palsy associated with a motor vehicle crash (95% CI +7 to +266, p=0.037). No significant increase was apparent for those with a term delivery (95% CI -62 to +79, p=0.510). A propensity score-matched analysis of preterm births (n=4384) yielded a 138% increased relative risk of cerebral palsy associated with a motor vehicle crash (95% CI +27 to +349, p=0.007), equal to an absolute increase of about 10.9 additional cases per 1000 newborns (18.2 vs 7.3, p=0.010).

CONCLUSIONS

Motor vehicle crashes during pregnancy may be associated with an increased risk of cerebral palsy among the subgroup of cases with preterm birth. The increase highlights a specific role for traffic safety advice in prenatal care.

An international study of the quality of national-level guidelines on driving with medical illness

BACKGROUND

Medical illnesses are associated with a modest increase in crash risk, although many individuals with acute or chronic conditions may remain safe to drive, or pose only temporary risks. Despite the extensive use of national guidelines about driving with medical illness, the quality of these guidelines has not been formally appraised.

AIM

To systematically evaluate the quality of selected national guidelines about driving with medical illness.

DESIGN

A literature search of bibliographic databases and Internet resources was conducted to identify the guidelines, each of which was formally appraised.

METHODS

Eighteen physicians or researchers from Canada, Australia, Ireland, USA and UK appraised nine national guidelines, applying the Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument.

RESULTS

Relative strengths were found in AGREE II scores for the domains of scope and purpose, stakeholder involvement and clarity of presentation. However, all guidelines were given low ratings on rigour of development, applicability and documentation of editorial independence. Overall quality ratings ranged from 2.25 to 5.00 out of 7.00, with modifications recommended for 7 of the guidelines. Intra-class coefficients demonstrated fair to excellent appraiser agreement (0.57-0.79).

CONCLUSIONS

This study represents the first systematic evaluation of national-level guidelines for determining medical fitness to drive. There is substantive variability in the quality of these guidelines, and rigour of development was a relative weakness. There is a need for rigorous, empirically derived guidance for physicians and licensing authorities when assessing driving in the medically ill.

Fibromyalgia and the Risk of a Subsequent Motor Vehicle Crash

OBJECTIVE

Motor vehicle crashes are a widespread contributor to mortality and morbidity, sometimes related to medically unfit motorists. We tested whether patients diagnosed with fibromyalgia (FM) have an increased risk of a subsequent serious motor vehicle crash.

METHODS

We conducted a population-based self-matched longitudinal cohort analysis to estimate the incidence rate ratio of crashes among patients diagnosed with FM relative to the population norm in Ontario, Canada. We included adults diagnosed from April 1, 2006, to March 31, 2012, excluding individuals younger than 18 years, living outside Ontario, lacking valid identifiers, or having only a single visit for the diagnosis. The primary outcome was an emergency department visit as a driver involved in a motor vehicle crash.

RESULTS

The patients (n = 137,631) accounted for 738 crashes during the first year of followup after diagnosis, equal to an incidence rate ratio of 2.44 compared with the population norm (95% CI 2.27-2.63, p < 0.001). The crash rate was more than twice the population norm for those with a new or a persistent diagnosis. The increased risk included patients with diverse characteristics, approached the rate observed among other patients diagnosed with alcoholism, and was mitigated among those who received dedicated FM care or a physician warning for driving safety.

CONCLUSION

A diagnosis of FM is associated with an increased risk of a subsequent motor vehicle crash that might justify medical interventions for traffic safety.

Pregnancy and the risk of a traffic crash

INTRODUCTION

Pregnancy causes diverse physiologic and lifestyle changes that may contribute to increased driving and driving error. We compared the risk of a serious motor vehicle crash during the second trimester to the baseline risk before pregnancy.

METHODS

We conducted a population-based self-matched longitudinal cohort analysis of women who gave birth in Ontario between April 1, 2006, and March 31, 2011. We excluded women less than age 18 years, those living outside Ontario, those who lacked a valid health card identifier under universal insurance, and those under the care of a midwife. The primary outcome was a motor vehicle crash resulting in a visit to an emergency department.

RESULTS

A total of 507,262 women gave birth during the study period. These women accounted for 6922 motor vehicle crashes as drivers during the 3-year baseline interval (177 per mo) and 757 motor vehicle crashes as drivers during the second trimester (252 per mo), equivalent to a 42% relative increase (95% confidence interval 32%-53%; p<0.001). The increased risk extended to diverse populations, varied obstetrical cases and different crash characteristics. The increased risk was largest in the early second trimester and compensated for by the third trimester. No similar increase was observed in crashes as passengers or pedestrians, cases of intentional injury or inadvertent falls, or self-reported risky behaviours.

INTERPRETATION

Pregnancy is associated with a substantial risk of a serious motor vehicle crash during the second trimester. This risk merits attention for prenatal care.