Table 2.
Medical cannabis safety outcome findings,1 by condition and study design type
| Total studies | Worsening | Mixed | No change | Inconclusive | |
|---|---|---|---|---|---|
| ALS | − | − | − | − | − |
| Autism | − | − | − | − | − |
| Cancer | 17 | 11 | 1 | − | 5 |
| Systematic reviews with meta-analysis | 4 | 3 [24, 220, 235] | − | − | 1 [221] |
| Systematic reviews | 9 | 4 [28, 39, 222, 236] | 1 [41] | − | 4 [32, 42, 223, 237] |
| RCTs | 2 | 2 [34, 225] | − | − | − |
| Observational or quasi-experimental studies | 2 | 2 [36, 43] | − | − | − |
| Chronic noncancer pain | 9 | 6 | 1 | − | 2 |
| Systematic reviews with meta-analysis | 4 | 2 [111, 226] | 1 [25] | − | 1 [114] |
| Systematic reviews | 5 | 4 [117, 119, 121, 122] | − | − | 1 [223] |
| Crohn's disease | 1 | 1 | − | − | − |
| Observational or quasi-experimental studies | 1 [132] | 1 [132] | − | − | − |
| Epilepsy | 18 | 10 | 1 | 5 | 2 |
| Systematic reviews with meta-analysis | 1 | 1 [138] | − | − | − |
| RCTs | 3 | 32 [136, 145, 153] | − | − | − |
| Observational or quasi-experimental studies | 14 | 6 [134, 140, 142, 151, 152, 154] | 1 [155] | 5 [135, 141, 144, 146, 238] | 2 [149, 150] |
| Glaucoma | − | − | − | − | − |
| HIV/AIDS | 5 | 3 | − | 2 | − |
| Systematic reviews with meta-analysis | 1 | 1 [120] | − | − | − |
| Observational or quasi-experimental studies | 4 | 2 [175, 239] | − | 2 [176, 177] | − |
| MS | 6 | 3 | − | 2 | 1 |
| Systematic reviews with meta-analysis | 3 | 2 [183, 184] | − | 1 [233] | − |
| Systematic reviews | 3 | 1 [180] | − | 1 [181] | 1 [223] |
| Parkinson's disease | 1 | − | − | 1 | − |
| Observational or quasi-experimental studies | 1 | − | − | 1 [186] | − |
| PTSD | 3 | − | 1 | − | 2 |
| Systematic reviews | 3 [195, 198, 199] | − | 1 [198] | − | 2 [195, 199] |
ALS, amyotrophic lateral sclerosis; HIV, human immunodeficiency virus; PTSD, posttraumatic stress disorder; RCT, randomized controlled trial; MS, multiple sclerosis. 1 Safety outcomes were defined in all studies as proportion of adverse events relative to placebo/active comparator, frequency of adverse events, or severity of adverse events relative to placebo/active comparator. Findings for safety outcomes were classified for cannabis/cannabinoid treatment according to the following: “worsening” if outcome worsened, “mixed” if multiple safety outcomes were assessed with divergent findings for each, “no change” if no change observed, and “inconclusive” if outcomes were unable to be assessed. 2 A secondary endpoint from one RCT, was deemed appropriate for inclusion in safety outcomes [136].