Summary of findings for the main comparison. Antioxidants compared to placebo or no treatment for patients with male subfertility.
| Antioxidants compared to placebo or no treatment for patients with male subfertility | ||||||
| Patient or population: patients with male subfertility Setting: clinic Intervention: antioxidants Comparison: placebo or no treatment | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with placebo or no treatment | Risk with antioxidants | |||||
| Live birth rate per couple randomised | 117 per 1000 | 192 per 1.000 (138 to 262) | OR 1.79 (1.20 to 2.67) | 750 (7 RCTs) | ⊕⊕⊝⊝ LOW 1 | |
| Clinical pregnancy rate per couple randomised | 69 per 1000 | 180 per 1.000 (124 to 255) | OR 2.97 (1.91 to 4.63) | 786 (11 RCTs) | ⊕⊕⊝⊝ LOW 1 | |
| Adverse events ‐ Miscarriage | 19 per 1000 | 33 per 1.000 (8 to 129) | OR 1.74 (0.40 to 7.60) | 247 (3 RCTs) | ⊕⊝⊝⊝ VERY LOW 1 2 | |
| Adverse events ‐ Gastrointestinal | 18 per 1000 | 45 per 1.000 (23 to 86) | OR 2.51 (1.25 to 5.03) | 948 (11 RCTs) | ⊕⊝⊝⊝ VERY LOW 1 3 | |
| *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; OR: Peto Odds ratio; | ||||||
| GRADE Working Group grades of evidence High certainty: We are very confident that the true effect lies close to that of the estimate of the effect Moderate certainty: 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 certainty: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect Very low certainty: 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 two levels for serious risk of bias: lack of allocation concealment, lack of blinding and incomplete accounting of patients and outcome events
2 Downgraded one level for serious imprecision: crossing the line of no effect
3 Downgraded one level for serious imprecision: incomplete accounting of patients and outcome events