Table 4. Summary risk estimates of the association between dietary cholesterol intake and endometrial cancer risk, dose-response analysis (per 100 mg/day increment).

	No. of study	Summary OR (95% CI)	I2 value (%)	Ph*	Ph**
Overall	10	1.06 (1.00–1.12)	64.2	< 0.01
Study design					0.43
Cohort study	1	1.00 (0.95–1.05)	N/A	N/A
Case-control study	9	1.07 (1.01–1.13)	59.5	0.01
Type of control subjects					0.55
Population-based	4	1.05 (0.95–1.15)	70.6	0.02
Hospital-based	5	1.09 (1.01–1.18)	45.4	0.12
Geographic location					0.64
North America	7	1.05 (0.98–1.11)	50.1	0.06
Europe	3	1.08 (0.96–1.22)	84.8	< 0.01
Validated FFQ					0.31
Yes	6	1.03 (0.96–1.11)	77.0	< 0.01
No	4	1.10 (1.03–1.18)	0	0.69
Number of cases					0.55
≥ 450	5	1.07 (1.01–1.14)	70.8	< 0.01
< 450	5	1.04 (0.92–1.17)	61.8	0.03
Adjustment for potential confounders
Total energy intake					0.98
Yes	9	1.06 (1.00–1.12)	68.2	< 0.01
No	1	1.06 (0.94–1.21)	N/A	N/A
Body mass index					0.69
Yes	8	1.05 (0.99–1.12)	71.4	< 0.01
No	2	1.08 (0.98–1.20)	0	0.57
Cigarette smoking					0.33
Yes	7	1.04 (0.99–1.10)	55.3	0.04
No	3	1.10 (0.97–1.25)	57.9	0.09
Parity					0.84
Yes	8	1.05 (0.99–1.13)	71.8	< 0.01
No	2	1.07 (0.99–1.16)	0	0.82
Oral contraceptive use					0.62
Yes	7	1.07 (1.00–1.14)	75.0	< 0.01
No	3	1.04 (0.97–1.12)	0	0.59
Menopausal status					0.86
Yes	7	1.06 (0.99–1.13)	74.8	< 0.01
No	3	1.06 (0.98–1.15)	0	0.51
Hormone replacement therapy use					0.65
Yes	8	1.06 (1.00–1.13)	70.9	< 0.01
No	2	1.03 (0.91–1.17)	5.9	0.30

CI, confidence interval; FFQ, food frequency questionnaire; N/A, not available; OR, odds ratio.

^*P-value for heterogeneity within each subgroup.

^**P-value for heterogeneity between subgroups with meta-regression analysis.