Table 3.
Summary of findings. GRADE Working Group grades of evidence. High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: We are very uncertain about the estimate
| Comparison | No. of participants (studies) | I2 (%) | GRADE | Relative effect (95% CI) | Anticipated absolute effects | ||
|---|---|---|---|---|---|---|---|
| Outcome | Risk with control | Risk difference with Cannabinoids | |||||
| Chronic pain | Dronabinol vs Placebo | 1395 (15 RCTs) | 53 |
⨁⨁⨁◯ MODERATE c |
SMD 0.31 lower (0.46 lower to 0.15 lower) |
||
| Dronabinol vs Active | 14 (1 RCT) |
SMD 0.73 higher (0.1 lower to 1.56 higher) |
|||||
| Nabilone vs Placebo | 363 (9 RCTs) | 70 |
⨁⨁◯◯ LOW c,g |
SMD 0.41 lower (0.76 lower to 0.06 lower) |
|||
| Nabilone vs Active | 262 (3 RCTs) | 83 |
⨁◯◯◯ VERY LOW c,e |
SMD 0.08 lower (0.54 lower to 0.38 higher) |
|||
| Cannabidiol vs Placebo | 129 (1 RCT) |
SMD 0.01 higher (0.34 lower to 0.35 higher) |
|||||
| Nabiximols vs Placebo | 3238 (21 RCTs) | 65 |
⨁⨁⨁◯ MODERATE c |
SMD 0.23 lower (0.34 lower to 0.12 lower) |
|||
| Spasticity | Dronabinol vs Placebo | 704 (6 RCTs) | 52 |
⨁⨁◯◯ LOW c,f |
SMD 0.08 lower (0.34 lower to 0.17 higher) |
||
| Nabilone vs Placebo | 44 (2 RCTs) | 68 |
⨁◯◯◯ VERY LOW a,c,g |
SMD 0.7 lower (1.56 lower to 0.16 higher) |
|||
| Nabiximols vs Placebo | 1658 (14 RCTs) | 68 |
⨁⨁⨁◯ MODERATE c |
SMD 0.36 lower (0.54 lower to 0.19 lower) |
|||
| Nausea/vomiting | Dronabinol vs Placebo | 495 (8 RCTs) | 61 |
⨁⨁◯◯ LOW c,f |
SMD 0 .21 lower (0.49 lower to 0.07 higher) |
||
| Dronabinol vs Active | 308 (5 RCTs) | 0 |
⨁⨁◯◯ LOW a,g |
SMD 0.28 lower (0.47 lower to 0.1 lower) |
|||
| Nabilone vs Placebo | 603 (4 RCTs) | 61 |
⨁⨁◯◯ LOW c,f |
SMD 0.09 lower (0.36 lower to 0.18 higher) |
|||
| Nabilone vs Active | 627 (11 RCTs) | 46 |
⨁⨁◯◯ LOW b,c |
SMD 0.44 lower (0.62 lower to 0.26 lower) |
|||
| Nabiximols vs Placebo | 393 (6 RCTs) | 56 |
⨁◯◯◯ VERY LOW a,e |
SMD 0.23 lower (0.55 lower to 0.08 higher) |
|||
| Appetite | Dronabinol vs Placebo | 599 (10 RCTs) | 81 |
⨁⨁⨁◯ MODERATE c |
SMD 0.51 lower (0.87 lower to 0.15 lower) |
||
| Dronabinol vs Active | 795 (3 RCTs) | 86 |
⨁⨁◯◯ LOW c,f |
SMD 0.02 lower (0.39 lower to 0.34 higher) |
|||
| Nabilone vs Placebo | 187 (4 RCTs) | 74 |
⨁◯◯◯ VERY LOW c,e |
SMD 0.44 lower (0.98 lower to 0.11 higher) |
|||
| Nabilone vs Active | 130 (3 RCTs) | 85 |
⨁◯◯◯ VERY LOW a,d, g |
SMD 0.24 higher (0.51 lower to 0.99 higher) |
|||
| Cannabidiol vs Placebo | 27 (1 RCT) |
SMD 0.1 higher (0.66 lower to 0.85 higher) |
|||||
| Nabiximols vs Placebo | 430 (6 RCTs) | 66 |
⨁⨁◯◯ LOW c,f |
SMD 0.25 lower (0.61 lower to 0.1 higher) |
|||
| Amyotrophic lateral sclerosis | Dronabinol vs Placebo | 22 (1 RCT) |
SMD 0.26 higher (0.17 lower to 0.68 higher) |
||||
| Nabiximols vs Placebo | 59 (1 RCT) |
SMD 0.38 higher (0.13 lower to 0.90 higher) |
|||||
| Chorea Huntington | Nabilone vs Placebo | 74 (1 RCT) |
SMD 0.45 lower (0.79 lower to 0.11 lower) |
||||
| Cannabidiol vs Placebo | 30 (1 RCT) |
SMD 0.18 higher (0.33 lower to 0.69 higher) |
|||||
| Nabiximols vs Placebo | 50 (1 RCT) |
SMD 0.17 higher (0.23 lower to 0.56 higher) |
|||||
| Dystonia | Dronabinol vs Placebo | 14 (1 RCT) |
SMD 0.05 higher (0.69 lower to 0.79 higher) |
||||
| Nabilone vs Placebo | 26 (1 RCT) |
SMD 0.49 lower (1.07 lower to 0.08 higher) |
|||||
| Nabiximols vs Placebo | 50 (1 RCT) |
SMD 0 (0.39 lower to 0.39 higher) |
|||||
| Epilepsy | Cannabidiol vs Placebo | 956 (6 RCTs) | 0 |
⨁⨁⨁⨁ HIGH |
SMD 0.5 lower (0.62 lower to 0.38 lower) |
||
| Glaucoma | Dronabinol vs Placebo | 12 (1 RCT) |
SMD 1.28 lower (2.36 lower to 0.2 lower) |
||||
| Nabiximols vs Placebo | 12 (1 RCT) |
SMD 0.82 higher (0.1 lower to 1.75 higher) |
|||||
| IBS | Dronabinol vs Placebo | 81 (2 RCTs) | 85 |
⨁◯◯◯ VERY LOW c,e |
SMD 0 (1.09 lower to 1.09 higher) |
||
| MS | Dronabinol vs Placebo | 660 (2 RCTs) | 74 |
⨁⨁◯◯ LOW c,f |
SMD 0.15 lower (0.51 lower to 0.22 higher) |
||
| Nabiximols vs Placebo | 863 (5 RCTs) | 65 |
⨁⨁◯◯ LOW c,f |
SMD 0.14 lower (0.38 lower to 0.11 higher) |
|||
| Parkinson | Nabilone vs Placebo | 51 (2 RCTs) | 46 |
⨁◯◯◯ VERY LOW c,e |
SMD 0.38 lower (1.05 lower to 0.29 higher) |
||
| Cannabidiol vs Placebo | 101 (3 RCTs) | 0 |
⨁⨁⨁◯ MODERATE g |
SMD 0.41 lower (0.75 lower to 0.08 lower) |
|||
| ADHD | Nabiximols vs Placebo | 30 (1 RCT) |
SMD 0.83 lower (1.58 lower to 0.09 lower) |
||||
| Anorexia nervosa | Dronabinol vs Placebo | 48 (1 RCT) |
SMD 0.47 lower (0.89 lower to 0.05 lower) |
||||
| Dronabinol vs Active | 22 (1 RCT) |
SMD 0.06 lower (0.65 lower to 0.53 higher) |
|||||
| Anxiety | Dronabinol vs Placebo | 113 (4 RCTs) | 49 |
⨁⨁◯◯ LOW e |
SMD 0.03 lower (0.47 lower to 0.41 higher) |
||
| Dronabinol vs Active | 278 (1 RCT) |
SMD 0.14 higher (0.03 lower to 0.31 higher) |
|||||
| Nabilone vs Placebo | 147 (6 RCTs) | 84 |
⨁◯◯◯ VERY LOW a,c,e |
SMD 0.59 lower (1.4 lower to 0.22 higher) |
|||
| Nabilone vs Active | 192 (2 RCTs) | 11 |
⨁⨁◯◯ LOW e |
SMD 0.11 lower (0.33 lower to 0.11 higher) |
|||
| Cannabidiol vs Placebo | 481 (11 RCTs) | 78 |
⨁◯◯◯ VERY LOW c,e |
SMD 0.34 lower (0.73 lower to 0.06 higher) |
|||
| Nabiximols vs Placebo | 258 (6 RCTs) | 43 |
⨁⨁◯◯ LOW e |
SMD 0.06 higher (0.23 lower to 0.34 higher) |
|||
| Dementia | Dronabinol vs Placebo | 115 (3 RCTs) | 3 |
⨁⨁◯◯ LOW e |
SMD 0.27 lower (0.57 lower to 0.04 higher) |
||
| Nabilone vs Placebo | 76 (1 RCT) |
SMD 0.53 lower (0.87 lower to 0.19 lower) |
|||||
| Depression | Dronabinol vs Placebo | 700 (7 RCTs) | 83 |
⨁⨁◯◯ LOW c,f |
SMD 0.15 lower (0.49 lower to 0.19 higher) |
||
| Dronabinol vs Active | 278 (1 RCT) |
SMD 0.14 higher (0.03 lower to 0.31 higher) |
|||||
| Nabilone vs Placebo | 76 (3 RCTs) | 0 |
⨁⨁◯◯ LOW e |
SMD 0.03 lower (0.48 lower to 0.43 higher) |
|||
| Nabilone vs Active | 192 (2 RCTs) | 0 |
⨁⨁◯◯ LOW e |
SMD 0.03 lower (0.23 lower to 0.17 higher) |
|||
| Cannabidiol vs Placebo | 301 (6 RCTs) | 0 |
⨁⨁◯◯ LOW e |
SMD 0.12 higher (0.09 lower to 0.34 higher) |
|||
| Nabiximols vs Placebo | 413 (7 RCTs) | 43 |
⨁⨁⨁◯ MODERATE f |
SMD 0.12 lower (0.36 lower to 0.13 higher) |
|||
| PTSD | Dronabinol vs Placebo | 46 (1 RCT) |
SMD 0.63 lower (1.22 lower to 0.03 lower) |
||||
| Nabilone vs Placebo | 18 (1 RCT) |
SMD 0.88 lower (1.65 lower to 0.11 lower) |
|||||
|
Schizophrenia /psychosis |
Dronabinol vs Placebo | 26 (1 RCT) |
SMD 0.89 higher (0.25 higher to 1.53 higher) |
||||
| Cannabidiol vs Placebo | 152 (3 RCTs) | 70 |
⨁◯◯◯ VERY LOW c,f |
SMD 0.24 lower (0.81 lower to 0.33 higher) |
|||
| Cannabidiol vs Active | 39 (1 RCT) |
SMD 0.05 higher (0.58 lower to 0.68 higher) |
|||||
| Sleep | Dronabinol vs Placebo | 683 (7 RCTs) | 64 |
⨁⨁◯◯ LOW c,f |
SMD 0.13 lower (0.39 lower to 0.12 higher) |
||
| Dronabinol vs Active | 22 (1 RCT) |
SMD 1.12 higher (0.37 higher to 1.87 higher) |
|||||
| Nabilone vs Placebo | 175 (6 RCTs) | 77 |
⨁◯◯◯ VERY LOW c,g |
SMD 0.58 lower (1.14 lower to 0.01 lower) |
|||
| Nabilone vs Active | 200 (2 RCTs) | 91 |
⨁◯◯◯ VERY LOW d,e |
SMD 0.21 lower (0.97 lower to 0.55 higher) |
|||
| Cannabidiol vs Placebo | 961 (8 RCTs) | 46 |
⨁⨁◯◯ LOW a,c |
SMD 0.06 lower (0.23 lower to 0.11 higher) |
|||
| Nabiximols vs Placebo | 3659 (23 RCTs) | 61 |
⨁⨁⨁◯ MODERATE c |
SMD 0.24 lower (0.35 lower to 0.14 lower) |
|||
| SUDs | Dronabinol vs Placebo | 196 (3 RCTs) | 0 |
⨁⨁◯◯ LOW a,g |
SMD 0.47 lower (0.73 lower to 0.2 lower) |
||
| Dronabinol vs Active | 60 (1 RCT) |
SMD 0.85 lower (1.41 lower to 0.29 lower) |
|||||
| Nabilone vs Placebo | 70 (3 RCTs) | 0 |
⨁⨁◯◯ LOW a,g |
SMD 0.55 lower (0.93 lower to 0.18 lower) |
|||
| Cannabidiol vs Placebo | 353 (7 RCTs) | 81 |
⨁◯◯◯ VERY LOW c,e |
SMD 0.2 lower (0.63 lower to 0.24 higher) |
|||
| Nabiximols vs Placebo | 237 (4 RCTs) | 59 |
⨁⨁⨁◯ MODERATE g |
SMD 0.48 lower (0.92 lower to 0.04 lower) |
|||
| Tourette | Dronabinol vs Placebo | 41 (2 RCTs) | 0 |
⨁⨁⨁◯ MODERATE g |
SMD 1.01 lower (1.58 lower to 0.44 lower) |
||
| Retention | Dronabinol vs Placebo | 3285 (37 RCTs) | 65 |
⨁⨁◯◯ LOW c,f |
OR 1.11 (0.80 to 1.53) |
194 per 1.000 |
17 more per 1.000 (33 fewer to 75 more) |
| Dronabinol vs Active | 1079 (8 RCTs) | 32 |
⨁◯◯◯ VERY LOW a,e |
OR 1.03 (0.76 to 1.40) |
422 per 1.000 |
7 more per 1.000 (65 fewer to 83 more) |
|
| Nabilone vs Placebo | 1070 (16 RCTs) | 0 |
⨁◯◯◯ VERY LOW a,e |
OR 0.99 (0.76 to 1.29) |
143 per 1.000 |
1 fewer per 1.000 (30 fewer to 34 more) |
|
| Nabilone vs Active | 1004 (13 RCTs) | 0 |
⨁◯◯◯ VERY LOW a,e |
OR 0.99 (0.79 to 1.25) |
205 per 1.000 |
2 fewer per 1.000 (36 fewer to 39 more) |
|
| Cannabidiol vs Placebo | 1775 (22 RCTs) | 41 |
⨁◯◯◯ VERY LOW c,g |
OR 1.38 (0.77 to 2.47) |
71 per 1.000 |
24 more per 1.000 (15 fewer to 88 more) |
|
| Nabiximols vs Placebo | 4643 (33 RCTs) | 44 |
⨁⨁◯◯ LOW c,f |
OR 1.17 (0.92 to 1.49) |
170 per 1.000 |
23 more per 1.000 (11 fewer to 64 more) |
|
| Adverse events | Dronabinol vs Placebo | 2707 (37 RCTs) | 56 |
⨁⨁◯◯ LOW c |
OR 2.16 (1.59 to 2.94) |
320 per 1.000 |
184 more per 1.000 (108 more to 260 more) |
| Dronabinol vs Active | 925 (8 RCTs) | 67 |
⨁⨁◯◯ LOW a,c |
OR 2.75 (1.43 to 5.26) |
466 per 1.000 |
240 more per 1.000 (89 more to 355 more) |
|
| Nabilone vs Placebo | 996 (16 RCTs) | 76 |
⨁⨁⨁◯ MODERATE c |
OR 3.12 (1.52 to 6.42) |
226 per 1.000 |
251 more per 1.000 (81 more to 426 more) |
|
| Nabilone vs Active | 909 (13 RCTs) | 71 |
⨁⨁◯◯ LOW a,c |
OR 2.47 (1.45 to 4.20) |
223 per 1.000 |
192 more per 1.000 (71 more to 324 more) |
|
| Cannabidiol vs Placebo | 1736 (22 RCTs) | 58 |
⨁⨁⨁◯ MODERATE c |
OR 1.82 (1.08 to 3.07) |
482 per 1.000 |
147 more per 1.000 (19 more to 259 more) |
|
| Nabiximols vs Placebo | 4404 (33 RCTs) | 74 |
⨁⨁⨁◯ MODERATE c |
OR 1.97 (1.48 to 2.64) |
536 per 1.000 |
159 more per 1.000 (95 more to 217 more) |
|
*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The risk difference (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI confidence interval, OR odds ratio. aModerate-High risk of bias; bMany high risk of bias; cModerate-Substantial heterogeneity; dHigh heterogeneity; eOptimal information size not met, CI overlaps no effect; fOptimal information size met, CI overlaps no effect; gOptimal information size not met, CI excludes no effect