Table 4 Summary risk estimates of the association between parity and endometrial cancer risk (parous versus nulliparous).
From: Parity and endometrial cancer risk: a meta-analysis of epidemiological studies
No of reports | RR (95% CI) | I2 (%) | P for heterogeneity | |
|---|---|---|---|---|
Overall | 42 | 0.69 (0.65–0.74) | 76.9 | <0.001 |
Subgroup analysis | ||||
Study design | ||||
Prospective | 7 | 0.66 (0.60–0.74) | 0.0 | 0.790 |
Case–control | 34 | 0.69 (0.64–0.74) | 79.7 | <0.001 |
Location | ||||
Europe | 15 | 0.76 (0.70–0.82) | 67.9 | <0.001 |
America | 17 | 0.71 (0.64–0.78) | 66.5 | <0.001 |
Asia | 9 | 0.53 (0.44–0.63) | 58.6 | 0.013 |
International | 1 | 0.73 (0.71–0.76) | — | — |
Number of cases | ||||
<200 | 19 | 0.68 (0.60–0.76) | 57.1 | 0.001 |
≥200 | 23 | 0.70 (0.65–0.75) | 83.3 | <0.001 |
Study publication time | ||||
Earlier than 1992 | 19 | 0.74 (0.68–0.82) | 63.0 | <0.001 |
1992– | 23 | 0.66 (0.61–0.71) | 82.8 | <0.001 |
Estimate adjustment | ||||
Yes | 33 | 0.68 (0.63–0.73) | 79.4 | <0.001 |
No | 9 | 0.72 (0.65–0.81) | 52.1 | 0.033 |
Estimate adjusted for age | ||||
Yes | 32 | 0.68 (0.63–0.73) | 80.1 | <0.001 |
No | 10 | 0.73 (0.66–0.81) | 47.3 | 0.048 |
Estimate adjusted for BMI | ||||
Yes | 10 | 0.63 (0.51–0.77) | 85.7 | <0.001 |
No | 32 | 0.71 (0.67–0.75) | 72.7 | <0.001 |
Estimate adjusted for smoking | ||||
Yes | 9 | 0.72 (0.61–0.85) | 75.5 | <0.001 |
No | 33 | 0.68 (0.64–0.73) | 77.8 | <0.001 |
Estimate adjusted for age, BMI and smoking | ||||
Yes | 8 | 0.71 (0.59–0.85) | 78.5 | <0.001 |
No | 34 | 0.69 (0.64–0.73) | 77.1 | <0.001 |
Sources of controls | ||||
Population based | 18 | 0.66 (0.60–0.73) | 82.9 | <0.001 |
Hospital based | 16 | 0.72 (0.63–0.83) | 76.3 | <0.001 |
Study quality | ||||
high | 31 | 0.67 (0.62–0.73) | 79.5 | <0.001 |
low | 10 | 0.72 (0.63–0.81) | 65.7 | 0.002 |
