Summary of findings 4.
Mifepristone (all doses) versus Yuzpe for emergency contraception
| Mifepristone (all doses) versus Yuzpe for emergency contraception | ||||||
| Patient or population: women seeking emergency contraception Setting: UK (3); family planning clinics Intervention: mifepristone (all doses) Comparison: Yuzpe | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Risk with Yuzpe | Risk with mifepristone (all doses) | |||||
| Observed number of pregnancies (all women) | 25 per 1000 | 3 per 1000 (1 to 10) | RR 0.14 (0.05 to 0.41) | 2144 (3 RCTs) | ⊕⊕⊕⊕ High | |
| Any side effect | 735 per 1000 | 610 per 1000 (566 to 647) | RR 0.83 (0.77 to 0.88) | 1693 (2 RCTs) | ⊕⊕⊕⊝ Moderate1 | |
| Specific side effects ‐ nausea | 424 per 1000 | 267 per 1000 (225 to 322) | RR 0.63 (0.53 to 0.76) | 2186 (3 RCTs) | ⊕⊕⊕⊝ Moderate1 | |
| Specific side effects ‐ vomiting | 135 per 1000 | 16 per 1000 (9 to 27) | RR 0.12 (0.07 to 0.20) | 2186 (3 RCTs) | ⊕⊕⊕⊕ High | |
| Specific side effects ‐ abdominal pain | 276 per 1000 | 210 per 1000 (168 to 262) | RR 0.76 (0.61 to 0.95) | 1000 (1 RCT) | ⊕⊕⊕⊝ Moderate2 | |
| Specific side effects ‐ spotting/bleeding after treatment | See comment | ‐ | ‐ | ‐ | No study reported this outcome | |
| Menses ‐ delay | 110 per 1000 | 311 per 1000 (253 to 381) | RR 2.83 (2.30 to 3.47) | 1924 (3 RCTs) | ⊕⊕⊕⊝ Moderate1 | |
| *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 | ||||||
| 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 | ||||||
1We downgraded the quality of evidence by one level for inconsistency because of high heterogeneity in the meta‐analysis. 2We downgraded the quality of evidence by one level for imprecision because the total (cumulative) sample size was lower than the calculated optimal information size.