Since 2001, treatment with medical cannabis has been permitted in Canada. In a recently published Canadian study, a team of researchers from the University of British Columbia in Vancouver examined the efficacy and safety of medical cannabis therapy based on real-world data.
Real-world data are data obtained from sources other than traditional clinical trials. Here, data were collected from 214 patients with various conditions via online survey. The most common conditions were chronic pain, post-traumatic stress disorder, anxiety, sleep disorders (including restless leg syndrome), arthritis, and other rheumatic diseases. Patients were interviewed both before treatment began and after 6 weeks. To assess changes in medical condition as well as quality of life, validated questionnaires were used by which patients could self-assess their current symptoms.
More than 60% of all patients showed an improvement in symptoms
Based on this online survey, more than 60% of all patients showed an improvement in symptoms. Specifically, patients suffering from recurrent pain reported a significant improvement in pain symptoms and an increase in quality of life after 6 weeks. Among these, 33% reported that a high-CBD medication helped them and 31% for whom a high-THC medication provided the most relief.
Treatment with medical cannabis significantly improved quality of life in patients with an anxiety disorder, and 85% of patients also reported partial improvement in anxiety symptoms. Patients with post-traumatic stress disorder also showed improvement in both symptoms and quality of life after 6 weeks of treatment.
Patients with arthritis and other rheumatic diseases experienced relief of pain and improvement in global activity, and patients with sleep disorders reported significant improvement in sleep problems.
The researchers also surveyed patients regarding potential side effects, 20% of whom reported mild side effects such as dry mouth, drowsiness, restlessness, and decreased memory at 6 weeks.
The 6-week treatment with medical cannabis resulted in significant symptomatic improvement in patients with recurrent pain, post-traumatic stress disorder, and sleep disorders. There was a significant increase in the quality of life of anxiety patients. Relief of pain and improvement in global activity were observed in patients with arthritis and other rheumatic diseases. No evidence of severe side effects was found.
Overall, 26% of all patients reported that the efficacy of medical cannabis was immediate.
Evidence on the efficacy of medical cannabis based on real-world data, in addition to results from clinical trials, will guide the design of future studies as well as primary care physicians and specialists when prescribing medical cannabis.
Cahill SP, Lunn SE, Diaz P, Page JE. Evaluation of patient reported safety and efficacy of cannabis from a survey of medical cannabis patients in Canada. Front Public Health 2021 (9):626853. Evaluation of Patient Reported Safety and Efficacy of Cannabis From a Survey of Medical Cannabis Patients in Canada