Evaluation of Patient Reported Safety and Efficacy of Cannabis From a Survey of Medical Cannabis Patients in Canada

Abstract

With the medical use of cannabis permitted in Canada since 2001, patients seek to use this botanical drug to treat a range of medical conditions. However, many healthcare practitioners express the need for further scientific evidence around the use of medical cannabis. This real-world evidence study aimed to address the paucity of scientific data by surveying newly registered medical cannabis patients, before beginning medical cannabis treatment, and at one follow up 6 weeks after beginning medical cannabis treatment. The goal was to collect data on efficacy, safety and cannabis product type information to capture the potential impact medical cannabis had on patient-reported quality of life (QOL) and several medical conditions over a 6-week period using validated questionnaires. The 214 participants were mainly male (58%) and 57% of the population was older than 50. The most frequently reported medical conditions were recurrent pain, post-traumatic stress disorder (PTSD), anxiety, sleep disorders [including restless leg syndrome (RLS)], and arthritis and other rheumatic disorders. Here we report that over 60% of our medical cannabis cohort self-reported improvements in their medical conditions. With the use of validated surveys, we found significant improvements in recurrent pain, PTSD, and sleep disorders after 6 weeks of medical cannabis treatment. Our 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. We also report that 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 QOL improvements. While these results show that patients find cannabis treatment effective for a broad range of medical conditions, cannabis was not a remedy for all the conditions investigated. Thus, there is a need for future clinical research to support the findings we have reported. Additionally, while real-world evidence has not historically been utilized by regulatory bodies, we suggest changes in public policy surrounding cannabis should occur to reflect patient reported efficacy of cannabis from real-world studies due to the uniqueness of medical cannabis's path to legalization.

Keywords: cannabidiol; medical cannabis; pain; post-traumatic stress disorder; quality of life; real-world data; sleep disorder; tetrahydrocannabinol.

Figure 1

Validated survey scores from the intake survey (baseline) and the 6-week follow-up survey for patients reporting recurrent pain. Overall POQ-SF, pain NRS score and the five subscales of the POQ-SF (see Supplementary Figure 2), showed improvements after 6 weeks of medical cannabis treatment. (A) Overall POQ-SF score significantly decreased after 6 weeks of medical cannabis treatment (t₁₈₂ = 6.74 P < 0.0001). (B) The pain NRS score reduced significantly (Wilcoxon test P < 0.001) from 6.2 ± 1.8/10 at baseline to 5.2 ± 2.1/10 at the 6-week follow-up. (C) EQ-VAS score significantly improved from the intake survey to the 6-week follow-up survey (t₁₈₂ = 3.53 P < 0.001), (****P < 0.0001, ***P < 0.001).

Figure 2

Validated survey scores from the intake survey (baseline) and 6-week follow-up survey for patients reporting nociceptive and neuropathic pain types. Overall POQ-SF and the pain NRS scores showed improvements following 6 weeks of medical cannabis treatment. (A,B). Nociceptive pain: (A) Overall POQ-SF score significantly decreased after 6 weeks of medical cannabis treatment (t₅₆ = 5.116 P < 0.0001). (B) The pain NRS score significantly improved (t₅₆ = 4.637 P < 0.0001) from 6.1 ± 1.7/10 at baseline to 4.9 ± 1.9/10 at the 6-week follow-up. (C,D). Neuropathic pain: (C) Overall POQ-SF score significantly decreased after 6 weeks of medical cannabis treatment (t₃₉ = 2.261 P < 0.05). (D) The pain NRS score significantly improved (t₃₉ = 2.994 P < 0.01) from 6.9 ± 1.5 /10 at baseline to 5.9 ± 2.1/10 at the 6-week follow-up, (****P < 0.0001, **P < 0.01, *P < 0.05).

Figure 3

Validated survey scores from the intake survey (baseline) and 6-week follow-up survey for patients reporting anxiety as their primary medical condition. There was an improvement in QOL after 6 weeks of medical cannabis treatment. (A) DASS-21 anxiety sub-scale scores were not significantly altered after 6 weeks of medical cannabis treatment (t₃₂ = 1.875 P = 0.07), but there was a trend toward improvement. (B) EQ-VAS score significantly improved from the intake survey to the 6-week follow-up survey (Wilcoxon test P < 0.001), (***P < 0.001, ⁺P = 0.07).

Figure 4

Validated survey scores from the intake survey (baseline) and 6-week follow-up survey for patients reporting PTSD as their primary medical condition. Overall, there was an improvement in patient's PTSD and QOL after 6 weeks of medical cannabis treatment. (A) SPRINT scores significantly decreased after 6 weeks of medical cannabis treatment (Wilcoxon test P < 0.0001). (B) EQ-VAS score significantly improved from the intake survey to the 6-week follow-up survey (t₃₁ = 4.072 P < 0.001), (****P < 0.0001, ***P < 0.001).

Figure 5

Validated survey scores from the intake survey (baseline) and 6-week follow-up survey for patients reporting arthritis or another rheumatic disorder as their primary medical condition. Overall while total PAS-II score did not improve, both the pain VAS and global activity VAS scores showed improvements after 6 weeks of medical cannabis treatment. (A) Total PAS-II score (Wilcoxon test P > 0.05) did not significantly change after 6 weeks of medical cannabis treatment. (B) The pain VAS score contained within the PAS-II (Wilcoxon test P < 0.05) significantly improved from the intake survey to 6-week follow-up survey. (C) The global activity VAS score contained within the PAS-II (Wilcoxon test P < 0.05) significantly improved after 6 weeks of medical cannabis treatment. (D) EQ-VAS score was not significantly altered from the intake survey to the 6-week follow-up survey (Wilcoxon test P = 0.09), though there was a small trend toward improvement. (*P < 0.05, +P = 0.09, NS P > 0.05).

Figure 6

Validated survey scores from the intake survey (baseline) and 6-week follow-up survey for patients reporting a sleep disorder (including RLS) as their primary medical condition. Overall, there were significant improvements in the PSQI scores after 6 weeks of medical cannabis treatment, but no significant change was found in the QOL score. (A) PSQI scores significantly improved after 6 weeks of medical cannabis treatment (Wilcoxon test P < 0.001). (B) EQ-VAS score did not significantly change from the intake survey to the 6-week follow-up survey (Wilcoxon test P > 0.05), (**P < 0.01, NS P > 0.05).