A new Canadian research project aims to be “one of the world’s largest studies on the therapeutic effects of medical cannabis.”

The program, launching in November at sites across the country, is sponsored by federally licensed cannabis producers Bedrocan Canada and Tweed Inc.

Up to 6,000 patients will participate in the study for three years to evaluate their quality of life before and after treatment with medical cannabis.

“Tens of thousands of Canadian patients are currently using cannabis to manage symptoms,” said Bedrocan Canada president Marc Wayne. “We are launching this study to advance the science associated with medical cannabis.”

The clinical study will launch with an initial three sites at Wellmedica in Woodbridge, Ontario, Greendot Medical Clinic in Brantford, Ontario, and Greenleaf Medical Clinic in Abbotsford, BC.

Greenleaf clinic director Fonda Betts said the study will give doctors more knowledge about cannabis dosage and type before prescribing to patients in the future.

More data, Betts said, “would give the physician more of a prescribing tool in terms of grams per day … as well as the best way to use their cannabis.”

The Canadian courts have ruled doctors can prescribe cannabis to patients, but Health Canada does not consider it an approved medication.

“The Government of Canada does not endorse the use of marijuana, but the courts have required reasonable access to a legal source of marijuana when authorized by a healthcare practitioner,” the government’s website stated.

The study’s principal investigator, Dr. Martin A. Katzman, said the study will provide the medical community with data on cannabis’s effects on different diagnoses and treatments.

“As the number of patients using medical cannabis increases, we have an urgent need to add to the body of literature and compile real-world data on who is using medical cannabis,” said Katzman. “No one in the medical community is recommending medical cannabis as a first-line therapy, but we know it is being used increasingly by patients refractory to conventional prescription drugs, or who cannot tolerate the side effects of conventional therapies.”

Changes to Canada’s medical cannabis program now require health care professionals to complete patients’ approval document for a prescription. With little medical information on cannabis available for professionals, the College of Family Physicians of Canada has approved seven programs on dried cannabis.

Bedrocan vice president of communications Cam Battley said the number of doctors authorized to prescribe cannabis increased 61 per cent in the first six months of 2015.