Summary of findings 4. Tibolone compared with combined HT for postmenopausal women: adverse events.
| Tibolone compared with combined HT for postmenopausal women: adverse events | ||||||
| Population: postmenopausal women with or without vasomotor symptoms Settings: outpatient or community Intervention: tibolone Comparison: combined HT | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | Number of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| Combined HT | Tibolone | |||||
| Unscheduled bleeding (all doses) Follow‐up: 3 to 36 months (median 12) | 474 per 1000 | 224 per 1000 (178 to 270) | OR 0.32 (0.24 to 0.41) | 6438 (16 studies) | ⊕⊕⊝⊝ moderatea | |
| Endometrial cancer (all doses) Follow‐up: 6.8 to 36 months (median 12) | See comments | OR 1.47 (0.23 to 9.33) | 3689 (5 studies) | ⊕⊝⊝⊝ very lowb,c | Events very rare in both groups. Total of 3 events: 2/1826 in tibolone group, 1/1863 in combined HT group | |
| Breast cancer; women without previous breast cancer (all doses) Follow‐up: 6.8 to 36 months (median 24) | 3 per 1000 | 6 per 1000 (3 to 13) |
OR 1.69 (0.78 to 3.67) | 4835 (5 studies) | ⊕⊝⊝⊝ very lowb,c | |
| Venous thromboembolic events (clinical evaluation; all doses) Follow‐up: 6.8 to 24 months (median 12) | 3 per 1000 | 1 per 1000 (0 to 6) |
OR 0.44 (0.09 to 2.14) | 4529 (4 studies) | ⊕⊝⊝⊝ very lowb,c | |
| Cardiovascular events (all doses) Follow‐up: 2 to 3 years | 17 per 1000 | 10 per 1000 (4 to 27) |
OR 0.63 (0.24 to 1.66) | 3794 (2 studies) | ⊕⊝⊝⊝ very lowb,c | |
| Cerebrovascular event (all doses) Follow‐up: 3.4 to 24 (median 9.4) months | 1 per 1000 | 1 per 1000 (0 to 3) |
OR 0.76 (0.16 to 3.66) | 4562 (4 studies) | ⊕⊝⊝⊝ very lowb,c | |
| Mortality from any cause (tibolone 2.5 mg/d) Follow‐up: 3.4 to 24 (median 9.4) months | See comments | OR 3.05 (0.12 to 75.2) | 970 (2 studies) | ⊕⊝⊝⊝ very lowb,c | Only 1 event (in tibolone group): 1/485 vs 0/485 | |
| *The basis for the assumed risk is the median control group risk across studies. The corresponding risk (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: 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 | ||||||
aDowngraded one level for serious risk of bias: poor reporting of study methods and potential conflict of interest in some studies
bDowngraded two levels for very serious risk of bias: poor reporting of study methods and potential conflict of interest in some studies
cDowngraded one level for serious imprecision: low event rate. Findings compatible with meaningful benefit in one or both arms, or with no effect