‘Drink Driving,’ Not Just Drunk Driving, Can Be Fatal.
Car crashes involving drivers with blood alcohol concentrations (BACs) below the legal limit of 0.08 percent account for 15 percent of alcohol-involved crash deaths in the United States, according to a new School of Public Health, School of Medicine, and Boston Medical Center study.
Published in the American Journal of Preventive Medicine, the study found that, of these deaths, 55 percent were of individuals other than the drinking driver. These crashes were also more likely to result in youth fatalities compared with crashes above the legal BAC limit.
Alcohol-involved motor vehicle accidents remain a leading cause of injury-related death in the US. Most research on crashes and alcohol focuses on alcohol above the legal limit of 0.08 percent, but cognitive impairment can begin at BACs as low as 0.03 percent. The National Transportation Safety Board and the National Academies of Sciences, Engineering, and Medicine have recommended reducing the legal blood alcohol concentration limit from 0.08 percent to 0.05 percent. In 2018, Utah became the first state to do so. Other countries have adopted this limit already and have seen decreases in motor vehicle crashes.
“Our study challenges the popular misconception that alcohol-involved crashes primarily affect drinking drivers, or that BACs below the legal limit don’t matter,” says study lead investigator Timothy Naimi, professor of community health sciences.
Naimi and colleagues analyzed 16 years of US motor vehicle crash data from the Fatality Analysis Reporting System with the Alcohol Policy Scale, a measure of state alcohol policies. From 2000 to 2015, 37 percent of more than 600,00 motor vehicle deaths occurred in crashes involving at least one driver with a detectable BAC. Of these, 15 percent were from crashes involving drivers with BACs below 0.08 percent.
The researchers also found that more restrictive alcohol policies were associated with a 9 percent decrease in the odds that a crash involved alcohol at levels below the legal limit. This relationship was consistent for multiple subgroups (such as only male drivers, or only female drivers) and at a blood alcohol cutoff of 0.05 percent.
“Lower alcohol crashes have been underestimated as a public health problem. Our research suggests that stringent alcohol policies reduce the likelihood of fatal accidents involving drivers with all levels of alcohol blood concentration,” says Naimi, who is also a professor of general internal medicine at the School of Medicine and a physician and alcohol epidemiologist at Boston Medical Center.
The study identified a number of policy approaches that could lead to a decrease in crash deaths involving alcohol at all levels, including increased alcohol taxes, required keg registration, and limited alcohol availability in grocery stores.
“Policies restricting impaired driving increase freedom from worry of injury or death for the majority of people on public roadways who are not drinking,” says the study’s lead author, Marlene Lira of the Clinical Addiction Research and Education (CARE) Unit at Boston Medical Center.
The study was co-authored by Timothy Heeren, professor of biostatistics and epidemiology. The other co-authors were Vishnudas Sarda of Boston Children’s Hospital, and Matthew Miller of Northeastern University.