A new study has found nearly half of Iowa drivers involved in a traffic crash tested positive for at least one drug.
The study by the National Highway Traffic Safety Administration screened people involved in crashes for drugs at seven Level 1 trauma centers nationally, ranging from Massachusetts to California.
The University of Iowa Hospitals and Clinics was one of the centers included.
The study tested seriously injured drivers who were brought to the UIHC's emergency room between August 2020 and July 2021.
The data show 45.3% of seriously injured drivers tested positive for at least one drug. The top two were alcohol and cannabinoids, which are products that come from cannabis plants. About 17% of drivers tested positive for either drug respectively.
The important thing to keep in mind is these are the more severe crashes that result in people being taken to a Level 1 trauma centers," said Timothy Brown, the director of drugged driving research at the University of Iowa National Advanced Driving Simulator.
"If you think about that around the country, it's not your your minor fender bender, where you're treated at the seat and then released. These are people who require more advanced care."
The prevalence of drugs in Iowa drivers was lower than the average nationally across all seven trauma centers.
According to the report, 54.2% of all drivers included in the study tested positive for at least one drug, with 21.4% testing positive for alcohol and 24.7% testing positive for cannabinoids.
It's unclear why Iowa drivers involved in crashes had lower rates of drug use, Brown said, but said the overall use of drugs like cannabinoids are increasing.
"The national landscape has changed," he said. "We're seeing decriminalization in Illinois, and there's greater access to product than there was 5,10 years ago."
The number of drivers who tested positive for prescription drugs also increased, a category of drugs people often overlook, Brown said.
"There are many, many medications out there that do great things for treating disease states, but they're not safe to drive with, and people just forget that," he said.
The study will help direct messaging so people understand when it is safe to operate a vehicle, but Brown said it shows all drivers should be on the look out when they're on the road.
"Your best bet is to be defensive and be aware of what else is going on," he said. "If you see a vehicle that's behaving badly, you want to give it space and you don't want to be in that zone around it if something bad happens."
