Medical Conditions and Crash Risk in Commercial Motor Vehicle Drivers

Diabetes and Driving: A Statement of the American Diabetes Association

Many people with diabetes in the U.S. will seek or currently hold a license to drive. For many, a driver's license is essential for everyday life. Considerable discussion has focused on whether, and the extent to which, diabetes may be a relevant factor in determining driver ability and eligibility for a license. This statement addresses such issues in relation to current scientific and medical evidence. A diagnosis of diabetes on its own is not sufficient to make judgments about an individual driver's ability or safety. This statement provides an overview of existing licensing rules for people with diabetes in the U.S., addresses the factors that affect driving ability, identifies general guidelines for assessing driver fitness and determining appropriately tailored licensing restrictions, and provides practical guidance for health care professionals regarding clinical interventions and education for people with diabetes.

A cross-sectional study of the prevalence of medical conditions as contributors to road crashes in South Australia

OBJECTIVES

With the population of Australians aged 85 or older expected to double by 2042 and the association of increased age with the greater likelihood of having medical conditions, the potential for an increase in the number crashes caused by medical conditions is of concern. This study aims to understand the prevalence of medical conditions contributing to road crashes and the characteristics of these crashes, in order to guide development of strategies to mitigate the risks and harms involved.

METHOD

The sample consisted of 1,934 active road users (drivers, motorcyclists, cyclists, pedestrians) injured in crashes on South Australian roads who were admitted to the Royal Adelaide Hospital over the period 2014 to 2017.

RESULTS

The findings indicate that 9.2% of hospital admission cases were directly caused by a medical condition or acute medical event, with loss of consciousness, attempted suicide, and seizures the most commonly observed. Crashes attributed to a medical condition were more likely to involve older drivers and those with a greater number of preexisting medical conditions.

CONCLUSION

Medical conditions or acute medical events are a significant contributor to road crashes. Common crash types involving medical conditions or events - single vehicle, hit object - indicate that vehicle technologies such as lane keeping assist and autonomous emergency braking, and infrastructure treatments such as roadside barriers, may help to prevent crashes in which a driver experiences a medical event. Monitoring of drivers with medical conditions should continue, while the benefits of social policies that reduce reliance on private motor vehicles for transport should also be explored.

Associations between vision impairment and vision-related interventions on crash risk and driving cessation: systematic review and meta-analysis

OBJECTIVES

To systematically investigate the associations between vision impairment and risk of motor vehicle crash (MVC) involvement, and evaluate vision-related interventions to reduce MVCs.

DESIGN

Medline (Ovid), EMBASE and Global Health electronic databases were systematically searched from inception to March 2022 for observational and interventional English-language studies. Screening, data extraction and appraisals using the Joanna Briggs Institute appraisal tools were completed by two reviewers independently. Where appropriate, measures of association were converted into risk ratios (RRs) or ORs for meta-analysis.

PARTICIPANTS

Drivers of four-wheeled vehicles of all ages with no cognitive declines.

PRIMARY AND SECONDARY OUTCOMES

MVC involvement (primary) and driving cessation (secondary).

RESULTS

101 studies (n=778 052) were included after full-text review. 57 studies only involved older drivers (≥65 years) and 85 were in high-income settings. Heterogeneity in the data meant that most meta-analyses were underpowered as only 25 studies, further split into different groups of eye diseases and measures of vision, could be meta-analysed. The limited evidence from the meta-analyses suggests that visual field defects (four studies; RR 1.51 (95% CI 1.23, 1.85); p<0.001; I2=46.79%), and contrast sensitivity (two studies; RR 1.40 (95% CI 1.08, 1.80); p=0.01, I2=0.11%) and visual acuity loss (five studies; RR 1.21 (95% CI 1.02, 1.43); p=0.03, I2=28.49%) may increase crash risk. The results are more inconclusive for available evidence for associations of glaucoma (five studies, RR 1.27 (95% CI 0.67, 2.42); p=0.47; I2=93.48%) and cataract (two studies RR 1.15 (95% CI 0.97, 1.36); p=0.11; I2=3.96%) with crashes. Driving cessation may also be linked with glaucoma (two studies; RR 1.62 (95% CI 1.20, 2.19); p<0.001, I2=22.45%), age-related macular degeneration (AMD) (three studies; RR 2.21 (95% CI 1.47, 3.31); p<0.001, I2=75.11%) and reduced contrast sensitivity (three studies; RR 1.30 (95% CI 1.05, 1.61); p=0.02; I2=63.19%). Cataract surgery halved MVC risk (three studies; RR 0.55 (95% CI 0.34, 0.92); p=0.02; I2=97.10). Ranibizumab injections (four randomised controlled trials) prolonged driving in persons with AMD.

CONCLUSION

Impaired vision identified through a variety of measures is associated with both increased MVC involvement and cessation. Cataract surgery can reduce MVC risk. Despite literature being highly heterogeneous, this review shows that detection of vision problems and appropriate treatment are critical to road safety.

PROSPERO REGISTRATION NUMBER

CRD42020172153.