For the study, published in the Annals of Internal Medicine, researchers also looked at the relationship between cannabis sales reported to the Colorado Marijuana Enforcement Division and emergency department visits. Although edible cannabis only made up 0.32% of sales in Colorado from 2014 to 2016, 10.7% of cannabis-related emergency department visits at UCHealth University of Colorado were due to edibles.

“There have been several high-profile deaths due to cannabis edibles but no documented death attributable to inhaled cannabis,” said lead study author Dr. Andrew A. Monte, a medical toxicologist and emergency medicine physician at UCHealth University of Colorado Hospital. “We observed a higher number of visits attributable to edibles than expected, and there was no data to determine if this was indeed true,” he said.

The researchers note that the study had some limitations, including that patients who go the emergency room “differ from the overall population of cannabis users, most of whom may use cannabis with no adverse effects.” Additionally, there was often no way to quantify the exact doses of cannabis, and researchers suspect that ingested doses may have exceeded inhaled doses.