The medical use of cannabis is permitted in Canada since 2001. In a recently published Canadian study, researchers from the University of British Columbia in Vancouver evaluated patient reported safety and efficacy of cannabis from a survey of medical cannabis patients in Canada.
Data was collected from 214 patients with various disorders via self-completed web-based surveys. The most frequently reported medical conditions were recurrent pain, post-traumatic stress disorder, anxiety, sleep disorders (including restless leg syndrome), and arthritis and other rheumatic disorders. Patients were asked to complete the survey before beginning medical cannabis treatment, and at one follow up 6 weeks after beginning medical cannabis treatment. To assess changes in reported medical conditions and quality of life measures, both validated questionnaires and self-reported changes in health outcomes were utilized.
Overall, over 60% of patients self-reported improvements in their medical conditions. More specifically, patients who reported they had recurrent pain experienced an improvement in their pain and overall quality of life after 6 weeks of medical cannabis treatment. Of those who rated cannabis as being helpful, 31% selected high THC products while 33% selected high CBD products.
In patients who reported anxiety as their primary medical condition, quality of life significantly improved from the intake survey to the 6-week follow-up survey, indicating that overall quality of life improved after 6 weeks of medical cannabis treatment for patients with anxiety. Patients also provided self-reported changes in their anxiety after 6 weeks of medical cannabis treatment, with 85% reporting some improvement in their anxiety. There was also a significant improvement in symptoms and quality of life in patients who reported post-traumatic stress disorder as their primary medical condition. After 6 weeks of medical cannabis treatment, patients with arthritis or another rheumatic disorder reported improvements specifically in pain and global activity, but not in their overall condition. 93% of the patients with sleep disorder reported some improvement in their sleep disorder.
Patients were also asked if they experienced any side effects – 20% reported mild side effects after 6 weeks of medical cannabis treatment, such as dry mouth, sleepiness, restlessness, and decreased memory.
With the use of validated surveys, researchers found significant improvements in recurrent pain, post-traumatic stress disorder, and sleep disorders after 6 weeks of medical cannabis treatment. Patients who stated anxiety as their main medical condition did not experience significant changes in their anxiety after 6 weeks of cannabis treatment, though there were improvements in quality of life. Findings from patients who reported arthritis and other rheumatic disorders are complex, showing improvements in pain and global activity sub-scores, but not overall changes in validated survey scores. No evidence for serious side effects was found.
When asked about how long patients found it took medical cannabis to affect their overall condition, 26% reported the effects of medical cannabis on their condition were experienced immediately.
Overall, the evaluation of patient reported efficacy of medical cannabis may inform future clinical research as well as healthcare practitioner practices around authorizing 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