New study examines cannabis use and emergency room visits

Emergency room visits and hospitalizations are 22 per cent higher among Canadians who use cannabis than among those who don't, according to a new study.

The study, led by researchers at Unity Health Toronto, compared data from almost 4,800 people who reported cannabis use in the preceding 12 months with data from more than 10,000 people who reported never having used cannabis.

It also controlled for more than 30 other factors that could have explained a hospital visit, including alcohol use, opioid use, prescription drug use, underlying mental health conditions and other underlying medical conditions.

"Our analyses are adjusted and controlled for all of these other factors, making it less likely that the other factors explain the positive emergency department visit and hospitalization finding," lead author Dr. Nicholas Vozoris told CTV News.

Among the causes for emergency room visits by cannabis users are acute bodily trauma, respiratory complaints, gastrointestinal problems, genitourinary complaints, miscellaneous problems, muscle or joint pain, infection, mental health, cardiovascular health, neurological complaints, dermatological complaints and cancer-related problems.

"For every 25 cannabis users, one will present within the year to the emergency department or be admitted to hospital for any cause," he said. “That's not a large number for every 25 users, but think about all the hundreds of thousands of people that are using cannabis across the province."

The study did not compare the rates of emergency room visits and hospitalizations among cannabis users to rates among people who use alcohol, opioids or other substances, and Vozoris said he's not aware of existing research that does compare these rates head-to-head. Vozoris said he hopes to compare these rates in future studies, in addition to looking at whether some forms of cannabis consumption are associated with higher rates of emergency room visits.

Vozoris says he was moved to study the relationship between cannabis use and hospital visits after treating high numbers of people who reported using sedating psychoactive medications in the course of his work in clinical respirology, lung health and sleep medicine.

"I was stunned by the amounts and combinations of sedating psychoactive medications people were on and it just struck me as a concern," he said. "And on top of all the psychoactive meds that are out there, there's been a large growth in cannabis and cannabis-related products."

Vozoris hopes the findings will help remind the public that cannabis use is not risk-free.