Summary of findings 1. Cannabinoids compared with placebo for chemotherapy‐induced nausea and vomiting.
| Cannabinoids compared with placebo for chemotherapy‐induced nausea and vomiting | ||||||
|
Patient or population: people with chemotherapy‐induced nausea and vomiting Intervention: cannabinoids Comparison: placebo | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| Placebo | Cannabinoids | |||||
|
Absence of nausea (follow‐up) |
3 per 100 | 6 per 100 (1 to 63) |
RR 2.0 (0.2 to 21) | 96 (2) | ⊕⊕⊝⊝ low3,5 | RR > 1 indicates treatment favours cannabinoids |
|
Absence of vomiting (follow‐up) |
6 per 100 | 34 per 100 (16 to 76) |
RR 5.7 (2.6 to 12.6) | 168 (3) | ⊕⊕⊝⊝ low3,5 | RR > 1 indicates treatment favours cannabinoids |
|
Absence of nausea and vomiting (follow‐up) |
11 per 100 | 32 per 100 (20 to 52) |
RR 2.9 (1.8 to 4.7) | 288 (3) | ⊕⊕⊕⊝ moderate3 | RR > 1 indicates treatment favours cannabinoids |
|
Participant preference (follow‐up) |
Low‐risk value2 | RR 4.8 (1.7 to 13) | 256 (2) | ⊕⊕⊝⊝ low3,4 | RR > 1 indicates treatment favours cannabinoids | |
| 8 per 100 | 38 per 100 (14 to 104) |
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| High‐risk value2 | ||||||
| 22 per 100 | 106 (37 to 286) |
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|
Withdrawal any reason (follow‐up) |
10 per 1000 | 3 per 1000 (0.1 to 7) |
RR 0.31 (0.01 to 7) | 33 (1) | ⊕⊝⊝⊝ very low1,3,5 | RR < 1 indicates treatment favours cannabinoids |
|
Withdrawal due to adverse event (follow‐up) |
80 per 1000 | 4 per 1000 (0.0 to 72) |
RR 6.9 (1.96 to 24) | 276 (2) | ⊕⊝⊝⊝ very low1,3,5 |
RR < 1 indicates treatment favours cannabinoids |
| *The assumed risk for all outcomes is the median control group risk across studies. The corresponding risk (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; RR: risk ratio. | ||||||
| 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. | ||||||
1 Sparse data.
2 The low‐ and high‐risk values are the two extreme proportions of people with a preference for one drug over another.
3 Limitations in the design (cross‐over study) and high attrition.
4 Unexplained heterogeneity.
5 Imprecision.