Table 2.
Summary risk estimates of the association between hormone replacement therapy and ovarian cancer.
| Subgroup | No. of studies | Pooled RR (95% CI) | I2 (%) | Pheterogeneity |
|---|---|---|---|---|
| All studies | 34 | 1.29 (1.19–1.40) | 57.4 | <0.001 |
| After excluding two studies (RR > 3.0) | 32 | 1.27 (1.17–1.37) | 52.1 | <0.001 |
| Study design | ||||
| Cohort studies | 15 | 1.35 (1.19–1.53) | 72.9 | <0.001 |
| Case control studies | 19 | 1.24 (1.11–1.38) | 30.4 | 0.103 |
| Hormones types | ||||
| HRT | 28 | 1.24 (1.15–1.35) | 51.6 | 0.001 |
| ERT | 6 | 1.85 (1.28–2.66) | 75.1 | 0.001 |
| Geographic location | ||||
| North America | 15 | 1.41 (1.23–1.61) | 45.5 | 0.028 |
| Europe | 15 | 1.22 (1.12–1.34) | 52.6 | 0.009 |
| Asia | 2 | 1.76 (1.09–2.85) | 4.8 | 0.305 |
| Australia | 2 | 0.96 (0.57–1.61) | 69.1 | 0.072 |
RR, relative risk; CI, confidence interval; HRT, hormone replacement therapy; ERT, estrogen replacement therapy.