The report details how the drug's legalization has affected state residents, including rates of usage, crime and effects on public health.
Hospitalizations involving patients with possible marijuana exposures and diagnoses increased from approximately 803 per 100,000 between 2001 and 2009 to 2,413 per 100,000 after marijuana was legalized and sold at retail stores, according to the report, which was unveiled Monday. Recreational marijuana was legalized for sale on Jan. 1, 2014, in Colorado.
Visits to emergency rooms also went up from an average of 739 per 100,000 patients between 2010 and 2013 to 956 per 100,000 after Jan. 1, 2014. The authors used specific billing codes that are used by hospitals to identify cannabis exposure and hallucinogen poising. They clarified that these codes do not prove that cannabis exposure was the main reason a patient was treated at the hospital.
"Use of these codes does not mean that the visit is motivated by marijuana exposure but simply that it is a possibility," the study authors said.
Dr. Andrew Monte, a toxicologist at the Department of Emergency Medicine at the University of Colorado, said he's not surprised to see an increase of hospital and ER visits related to marijuana use.
The smallest group is made up of "people who come in intoxicated," Monte said. "We only see one or two for marijuana intoxication. I would say disproportionately we see edible agents lead to more intoxication."
"The point always needs to be made that there have clearly been positives from marijuana liberalization from a social perspective and medical perspective," Monte said. "It allows us to examine marijuana use for medical conditions where we couldn’t do that before."
More study is needed to mitigate the negative effects of the liberalization, Monte said, but health officials have been working to do that since the drug's legalization.
In addition to the findings on hospital visits, the new report found arrests related to marijuana have gone down about 46 percent before and after legalization. Usage has gone up significantly for adults, especially young adults between the ages of 18 to 25 years old, the report found. About 31 percent of young adults reported using the drug at least once in the last 30 days in 2014 compared to 21 percent in 2006.
Among adolescents, researchers found that about 12.6 percent of those between the ages of 12 and 17 reported using marijuana within the last 30 days in 2014 compared to 10.2 percent in 2009.