Race plays a role in drowsy driving in the U.S. with a recent study confirming that Blacks and Hispanics have approximately twice the risk of dozing off while behind the wheel compared to Caucasians.

While previous reports have shown a link between race and drowsy driving, the reasons remain unclear. 

This latest study by researchers from the University of Pittsburgh School of Medicine and published in Sleep Health, explores the mechanisms of racial disparity is drowsy driving. The authors conclude that differences in sleep quality explain some of the disparity in Blacks, but not in the Hispanic population.

The authors analyzed responses from 193,776 White, Black and Hispanic adults who took surveys conducted by the Centers for Disease Control and Prevention between 2009 and 2012. Participants were asked a question about whether or not they had fallen asleep while driving in the past 30 days.

After adjusting for other factors, researchers found that compared with Whites, Blacks had double the risk of having experienced a drowsy driving incident and Hispanics were 80% more likely to self-report one, notes a report about the study in Reuters.

People who reported falling asleep while driving were younger, predominantly male, and had a higher body mass index compared to people who said they had not nodded off behind the wheel in the past month. In addition, the drowsy drivers were more likely to experience daytime sleepiness, be dissatisfied with their sleep quality and get less than seven hour of sleep per night, reports Reuters.

The authors say that further research is needed to understand the root causes of the drowsy driving disparities among racial groups. However, they emphasize that higher incidents of drowsy driving among Blacks and Hispanics does not appear to be due to alcohol use, risk-taking behaviors or economic barriers to healthcare.

Read the study here.

Related: Distracted Driving: Men vs. Women