Summary of findings 3. Acupuncture compared to prophylactic drugs.
| Acupuncture compared to prophylactic drugs | ||||||
| Patient or population: people with episodic migraine Setting: primary care or outpatient care Intervention: acupuncture Comparison: prophylactic drug treatment | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Risk with prophylactic drug treatment | Risk with acupuncture | |||||
| Headache frequency assessed with days per month follow‐up median 3 months | Headache frequency was 0.25 SDs (‐039 to ‐0.10) lower than in the groups receiving prophylactic drug treatment | ‐ | 739 (3 RCTs) | ⊕⊕⊕⊝ MODERATE 1 | As a rule of thumb 0.2 SD represents a small difference, 0.5 a moderate, and 0.8 a large difference. Size of difference open to change with more trials | |
| Headache frequency assessed with days per month follow‐up: median 6 months | Headache frequency was 0.13 SDs (‐0.28 to 0.01) lower than in the groups receiving prophylactic drug treatment | ‐ | 744 (3 RCTs) | ⊕⊕⊕⊝ MODERATE 1 | As a rule of thumb 0.2 SD represents a small difference, 0.5 a moderate, and 0.8 a large difference. Size of difference open to change with more trials | |
| Response assessed with proportion of participants with at least 50% headache frequency reduction follow‐up: median 3 months | Study population | RR 1.24 (1.08 to 1.44) | 743 (3 RCTs) | ⊕⊕⊕⊝ MODERATE 1 | Due to the limited number of trials and risk of bias size of differences open to change with more trials | |
| 461 per 1000 | 572 per 1000 (498 to 664) | |||||
| Response assessed with proportion of participants with at least 50% headache frequency reduction follow‐up: median 6 months | Study population | RR 1.11 (0.97 to 1.26) | 744 (3 RCTs) | ⊕⊕⊕⊝ MODERATE 1 | Due to the limited number of trials and risk of bias size of differences open to change with more trials | |
| 536 per 1000 | 595 per 1000 (520 to 675) | |||||
| Number of participants dropping out due to adverse effects | Study population | OR 0.27 (0.08 to 0.86) | 451 (4 RCTs) | ⊕⊕⊕⊝ MODERATE 2 | Consistent results between studies, but uncertainty about size of difference due to low frequency of events in acupuncture group | |
| 71 per 1000 | 20 per 1000 (6 to 62) | |||||
| Number of participants reporting adverse effects | Study population | OR 0.25 (0.10 to 0.62) | 931 (5 RCTs) | ⊕⊕⊕⊝ MODERATE 3 | Consistently fewer adverse effects in acupuncture groups, but strong variability of size of differences (probably due to different assessment methods) | |
| 341 per 1000 | 114 per 1000 (49 to 243) | |||||
| *The risk in the intervention group (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; OR: Odds ratio; | ||||||
| GRADE Working Group grades of evidence High quality: We are very confident that the true effect lies close to that of the estimate of the effect Moderate quality: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different Low quality: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect Very low quality: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect | ||||||
1 Downgraded once: in two of three studies a relevant proportion of participants randomized to drug treatment dropped out early (analysis included only participants receiving at least a minimal amount of treatment); no blinding of participants
2 Downgraded once: few events in acupuncture group; wide confidence interval
3 Downgraded once: size of differences highly variable (I² = 78%; Chi² = 17.95, P value = 0.001), but consistently more adverse effects in drug groups