Summary of findings for the main comparison. Metformin versus placebo co‐treatment for assisted reproduction for subfertility associated with polycystic ovary syndrome.
| Metformin versus placebo co‐treatment for assisted reproduction for subfertility associated with polycystic ovary syndrome | ||||||
| Patient or population: patients with subfertility associated with polycystic ovary syndrome Settings: outpatient Intervention: metformin vs placebo co‐treatment for assisted reproduction | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | Number of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| Placebo co‐treatment | Metformin co‐treatment | |||||
| Live birth rate (per woman) Follow‐up: 3‐6 months | 267 per 1000 |
457 per 1000 190 more per 1000 (42 to 345) |
OR 2.31 (1.24 to 4.33) | 180 (2 studies) | ⊕⊕⊝⊝ Lowa | |
| Multiple pregnancy rate (per woman) | 52 per 1000 |
26 per 1000 23 fewer per 1000 (44 fewer to 25 more) |
OR 0.55 (0.15 to 1.95) |
232 (4 studies) | ⊕⊕⊝⊝ Lowa,b | |
| Ongoing pregnancy rate (per woman) | 217 per 1000 |
393 per 1000 189 more per 1000 (57 to 336) |
OR 2.46 (1.36 to 4.46) | 232 (4 studies) | ⊕⊕⊝⊝ Lowa | |
| Clinical pregnancy rate (per woman) | 252 per 1000 |
444 per 1000 206 more per 1000 (78 to 340) |
OR 2.51 (1.46 to 4.31) | 264 (5 studies) | ⊕⊕⊝⊝ Lowa | |
| *The basis for the assumed risk (e.g. median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: confidence interval; OR: odds 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. | ||||||
aLimited sample size, limited precision, lack of blinding of participants and of outcome assessors. bMultiple pregnancy had a very low incidence.