Summary of findings for the main comparison. Acupoint PC6 stimulation versus sham for preventing postoperative nausea and vomiting.
| Acupoint PC6 stimulation versus sham for preventing postoperative nausea and vomiting | ||||||
|
Patient or population: People at risk of postoperative nausea and vomiting
Settings: Surgery
Intervention: Acupoint PC6 stimulation Comparison: Sham | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of Participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| Sham | Acupoint PC6 stimulation | |||||
| Nausea ‐ All trials | Low | RR 0.68 (0.60 to 0.77) | 4742 (40 studies) | ⊕⊕⊝⊝ low1,2 | ||
| 200 per 1000 | 136 per 1000 (120 to 154) | |||||
| Moderate | ||||||
| 400 per 1000 | 272 per 1000 (240 to 308) | |||||
| High | ||||||
| 600 per 1000 | 408 per 1000 (360 to 462) | |||||
| Vomiting ‐ All trials | Low | RR 0.60 (0.51 to 0.71) | 5147 (45 studies) | ⊕⊕⊝⊝ low2,3 | ||
| 200 per 1000 | 120 per 1000 (102 to 142) | |||||
| Moderate | ||||||
| 400 per 1000 | 240 per 1000 (204 to 284) | |||||
| High | ||||||
| 600 per 1000 | 360 per 1000 (306 to 426) | |||||
| Rescue antiemetics | 329 per 1000 | 210 per 1000 (181 to 240) | RR 0.64 (0.55 to 0.73) | 4622 (39 studies) | ⊕⊕⊝⊝ low4,5 | |
| Adverse effects | Not estimable | Not estimable | Not estimable | 35 studies6 | Not applicable | See footnote6 |
| *The basis for the assumed risks for nausea and vomiting is from a consensus panel (Gan 2014) using Apfel's simplified risk score (Apfel 1999). The assumed risk for rescue antiemetic is the median sham 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. | ||||||
1Of the 40 trials, 13 had one or more high risk of bias domains (downgrade 1 point due to study limitations). 2Substantial amount of heterogeneity (downgrade 1 point due to inconsistency). 3Of the 45 trials, 16 had one or more high risk of bias domains (downgrade 1 point due to study limitations). 4Moderate amount of heterogeneity (downgrade 1 point due to inconsistency). 5Of the 39 trials, 13 had one or more high risk of bias domains (downgrade 1 point due to study limitations). 6Twenty‐two trials reported no adverse side effects. Minor, self‐limiting and transient adverse effects reported in 13 studies (haematoma, redness, irritation and pain at acupuncture site; redness, swelling, discomfort, blistering at acupoint site when wearing acupressure wristband).