Summary of findings 2. Mid‐dose mifepristone (25 mg‐50 mg) versus levonorgestrel 1.5 mg for emergency contraception.
| Mid‐dose mifepristone (25 mg‐50 mg) compared to levonorgestrel 1.5 mg for emergency contraception | ||||||
| Patient or population: women seeking emergency contraception Setting: China (27); family planning clinics Intervention: mifepristone, mid‐dose (25 mg‐50 mg) Comparison: levonorgestrel 1.5 mg | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Risk with levonorgestrel 1.5 mg | Risk with mid‐dose mifepristone (25 mg‐50 mg) | |||||
| Observed number of pregnancies (all women) | 35 per 1000 | 21 per 1000 (16 to 29) | RR 0.61 (0.45 to 0.83) | 6052 (27 RCTs) | ⊕⊕⊕⊝ Moderate1 | |
| Any side effect | 202 per 1000 | 111 per 1000 (81 to 150) | RR 0.55 (0.40 to 0.74) | 4352 (18 RCTs) | ⊕⊕⊝⊝ Low1,2 | |
| Specific side effect ‐ nausea | 80 per 1000 | 65 per 1000 (39 to 109) | RR 0.81 (0.48 to 1.36) | 713 (4 RCTs) | ⊕⊕⊝⊝ Low1,3 | |
| Specific side effect ‐ vomiting | See comment | ‐ | ‐ | ‐ | No study reported this outcome | |
| Specific side effect ‐ spotting/bleeding after treatment | 77 per 1000 | 47 per 1000 (32 to 68) | RR 0.61 (0.42 to 0.88) | 1796 (9 RCTs) | ⊕⊕⊝⊝ Low1,3 | |
| Menses ‐ early | 94 per 1000 | 68 per 1000 (47 to 97) | RR 0.72 (0.50 to 1.03) | 1324 (7 RCTs) | ⊕⊕⊝⊝ Low1,3 | |
| Menses ‐ delay | 108 per 1000 | 139 per 1000 (117 to 166) | RR 1.29 (1.09 to 1.54) | 3615 (17 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 serious risk of bias associated with poor reporting of randomization methods. 2We downgraded the quality of evidence by one level for inconsistency because of high heterogeneity in the meta‐analysis. 3We downgraded the quality of evidence by one level for imprecision because the total (cumulative) sample size was lower than the calculated optimal information size.