Table 6 Summary risk estimates of the association between parity and endometrial cancer risk (parity number of 2 versus nulliparous).
From: Parity and endometrial cancer risk: a meta-analysis of epidemiological studies
No of reports | RR (95% CI) | I2 (%) | P for heterogeneity | |
|---|---|---|---|---|
Parity number of 2 vs. nulliparous | 13 | 0.62 (0.53–0.74) | 92.1 | <0.001 |
Subgroup analysis | ||||
Study design | ||||
Prospective | 2 | 0.54 (0.31–0.93) | 92.7 | <0.001 |
Case-control | 10 | 0.63 (0.53–0.76) | 68.8 | 0.001 |
Location | ||||
Europe | 7 | 0.61 (0.43–0.86) | 95.3 | <0.001 |
America | 3 | 0.66 (0.54–0.80) | 0.0 | 0.835 |
Asia | 2 | 0.49 (0.31–0.78) | 52.7 | 0.146 |
International | 1 | 0.78 (0.75–0.81) | — | — |
Number of cases | ||||
<200 | 5 | 0.60 (0. 48–0.74) | 16.2 | 0.312 |
≥200 | 8 | 0.64 (0.52–0.78) | 95.1 | <0.001 |
Study publication time | ||||
Earlier than 1992 | 5 | 0.68 (0.58–0.79) | 0.0 | 0.957 |
1992- | 8 | 0.59 (0.47–0.74) | 95.4 | <0.001 |
Estimate adjustment | ||||
Yes | 11 | 0.59 (0.46–0.77) | 92.5 | <0.001 |
No | 2 | 0.78 (0.75–0.81) | 0.0 | 0.417 |
Estimate adjusted for age | ||||
Yes | 11 | 0.59 (0.46–0.77) | 92.5 | <0.001 |
No | 2 | 0.78 (0.75–0.81) | 0.0 | 0.417 |
Estimate adjusted for BMI | ||||
Yes | 4 | 0.50 (0.29–0.85) | 79.5 | 0.002 |
No | 9 | 0.66 (0.54–0.79) | 94.0 | <0.001 |
Estimate adjusted for smoking | ||||
Yes | 3 | 0.55 (0.27–1.09) | 80.1 | 0.007 |
No | 10 | 0.63 (0.53–0.76) | 93.7 | <0.001 |
Estimate adjusted for age, BMI and smoking | ||||
Yes | 3 | 0.55 (0.27–1.09) | 80.1 | 0.007 |
No | 10 | 0.63 (0.53–0.76) | 93.7 | <0.001 |
Study quality | ||||
high | 9 | 0.56 (0.44–0.73) | 82.1 | <0.001 |
low | 3 | 0.74 (0.59–0.92) | 52.1 | 0.124 |
