Table 1.

Descriptive characteristics of invasive breast cancer cases (N= 5,707) and controls (N= 6,389)

	Cases		Controls
	N1	%	N1	%	OR2 (95% CI)
Age
<50	2044	35.8	2238	35.0	1.0 (ref)
50–59	1955	34.3	2304	36.1	0.92 (0.84 – 1.00)
>59	1708	29.9	1847	28.9	1.00 (0.91 – 1.09)
Race
Caucasian	5512	96.6	6110	95.6	1.0 (ref)
Not Caucasian	163	2.9	242	3.8	0.75 (0.62 – 0.90)
Education
≥ 12 years	2566	45.1	2915	45.9	1.0 (ref)
1–3 years college	1496	26.3	1717	26.9	1.01 (0.93 – 1.11)
College graduate	1631	28.6	1742	27.3	1.12 (1.03 – 1.23)
Body mass index (kg/m2)
Premenopausal
<24	1102	46.8	1131	43.9	1.0 (ref)
24–27	669	28.4	737	28.6	0.94 (0.81 – 1.07)
>27	584	24.8	707	27.5	0.82 (0.71 – 0.95)
Postmenopausal
<24	973	31.5	1158	33.2	1.0 (ref)
24–27	1044	33.8	1142	32.7	1.07 (0.95 – 1.21)
>27	1069	34.6	1192	34.1	1.04 (0.92 – 1.17)
Age at menarche
<12	1227	21.5	1284	20.1	1.0 (ref)
12–14	3827	67.1	4261	66.7	0.93 (0.85 – 1.02)
>14	595	10.4	785	12.3	0.78 (0.67 – 0.89)
Parity
Nulliparous	812	14.2	769	12.0	1.0 (ref)
1–2	2508	43.9	2567	40.2	0.92 (0.82 – 1.03)
>2	2381	41.7	3047	47.7	0.69 (0.61 – 0.77)
Menopausal status
Premenopausal	2363	43.2	2594	42.0	1.0 (ref)
Postmenopausal	3110	56.8	3516	57.5	0.87 ( 0.77 – 0.97)
Family history of breast cancer
No	4525	79.2	5536	86.7	1.0 (ref)
Yes	1150	20.1	817	12.8	1.58 (1.41 – 1.78)
History of benign breast disease
No	3899	68.3	4885	76.5	1.0 (ref)
Yes	1752	30.7	1445	22.6	1.10 (1.06 – 1.15)
Recent alcohol consumption (drinks/week)
0	983	17.2	1119	17.5	1.0 (ref)
<2	2526	44.3	3012	47.2	0.95 (0.86 – 1.05)
2 – <4	786	13.8	862	13.5	1.04 (0.91 – 1.18)
4+	1407	24.7	1391	21.8	1.18 (1.05 – 1.32)
Smoking
Never smokers	2667	46.8	2945	46.3	1.0 (ref)
Ever smokers	3034	53.2	3437	53.8	1.00 (0.93 – 1.08)
Multivitamin use
No	3166	56.9	3462	55.5	1.0 (ref)
Yes	2403	43.1	2782	44.5	0.94 (0.87 – 1.01)

¹Column totals are unequal due to missing data

²Odds ratios are adjusted for age and state of residence