Table 4.

Odds ratio for dense breast among postmenopausal women. In the multivariate analysis, adjusted by age, BMI, smoking status, alcohol status, and hormonal therapy, parity still showed a significant relationship. Compared with women with more than two parity, two parity, single parity and nulliparity had a higher risk of dense breast (OR: 1.849 (95% CI; 1.479–2.312), OR: 3.023 (95% CI; 2.385–3.830), OR: 4.954 (95% CI; 3.975–6.174), respectively)

	Univariate	p	Multivariate	p
Age	0.941 (0.933–0.947)	< 0.001	0.959 (0.952–0.966)	< 0.001
BMI	0.751 (0.736–0.765)	< 0.001	0.753 (0.737–0.768)	< 0.001
Parity
0	6.322 (5.143–7.772)	< 0.001	4.954 (3.975–6.174)	< 0.001
1	4.013 (3.214–5.012)	< 0.001	3.023 (2.385–3.830)	< 0.001
2	2.124 (1.717–2.628)	< 0.001	1.849 (1.479–2.312)	< 0.001
≥ 3 (ref)	–	–	–	–
Trend*	0.565 (0.539–0.592)	< 0.001	0.575 (0.543–0.610)	< 0.001
Smoking status
Never (ref)	–	–	–	–
Past	1.122 (0.984–1.280)	0.085	1.040 (0.894–1.209)	0.612
Current	1.385 (1.095–1.753)	0.007	0.946 (0.723–1.238)	0.684
Alcohol status
Non (ref)	–	–	–	–
Occasional	1.320 (1.150–1.514)	< 0.001	1.320 (1.129–1.542)	< 0.001
Regular	1.757 (1.589–1.943)	< 0.001	1.250 (1.113–1.404)	< 0.001
Family history of breast cancer	1.031 (0.915–1.162)	0.612	–	–
Hormonal therapy	1.355 (1.195–1.536)	< 0.001	0.975 (0.846–1.123)	0.722

*To calculate p for trend, variables were modeled as continuous value