Summary of findings for the main comparison. Exposure to any ovary‐stimulating drugs for subfertility compared to untreated subfertile women and endometrial cancer risk.
| Patient or population: Women treated with ovary‐stimulating drugs for subfertility Intervention: Exposure to any ovary‐stimulating drug for subfertility Comparison: Untreated subfertile women | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Risk with no treatment | Risk with exposure to any ovary‐stimulating drug for subfertility | |||||
| Endometrial cancer | Study population | RR 0.96 (0.67 to 1.37) | 156,774 (6 observational studies) | ⊕⊝⊝⊝ Very low 1,2,3 | ||
| 111 per 100,000 | 109 per 100,000 (74 to 163) | |||||
| *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 | ||||||
1 Initial level of evidence was 'low' because of the study design (observational studies). 2 Downgraded because of high risk of bias. 3Optimal information size (OIS) criterion not met (OIS = 499,938); however, the sample size was large.