Exploring the mechanisms of the racial disparity in drowsy driving

Drowsy driving is a significant cause of traffic accidents and fatalities. Although previous reports have shown an association between race and drowsy driving, the reasons for this disparity remain unclear.

A cross-sectional analysis of responses from 193,776 White, Black, and Hispanic adults participating in the US Behavioral Risk Factor Surveillance System from 2009 to 2012 who answered a question about drowsy driving.

Drowsy driving was defined as self-reporting an episode of falling asleep while driving in the past 30 days. All analyses were adjusted for age, sex, and medical comorbidities. Subsequent modeling evaluated the impact of accounting for differences in health care access, alcohol consumption, risk-taking behaviors, and sleep quality on the race-drowsy driving relationship.

After adjusting for age, sex, and medical comorbidities, the odds ratio (OR) for drowsy driving was 2.07 (95% confidence interval [CI] 1.69-2.53) in Blacks and 1.80 (95% CI 1.51-2.15) in Hispanics relative to Whites. Accounting for health care access, alcohol use, and risk-taking behaviors had little effect on these associations. Accounting for differences in sleep quality resulted in a modest reduction in the OR for drowsy driving in Blacks (OR = 1.55, 95% CI 1.27-1.89) but not Hispanics (OR = 1.74, 95% CI 1.45-2.08).

US Blacks and Hispanics have approximately twice the risk of drowsy driving compared to whites. Differences in sleep quality explained some of this disparity in Blacks but not in Hispanics. Further research to understand the root causes of these disparities is needed.