Table 1. Characteristics of study participants.

Characteristic	Study samples (n = 121)
	No.	Mean (range) or %
Demographic and clinical characteristics
Age, years	121	38	(17–76)
Race
European American	81		67%
African American	40		33%
BMI, kg/m2	121	30	(21–46)
Age at menarche	91	13	(9–16)
Missing	30	-
Parity
Nulliparous	53		55%
1	14		14%
2	20		21%
3+	10		10%
Missing	24	-
Age at first birth, years	34	27	(17–38)
Missing	87	-
Alcohol statusa
Ever drinker	99		88%
Never drinker	14		12%
Missing	8	-
Smoking statusb
Ever smoker	33		34%
Never smoker	65		66%
Missing	23
Menopausal status
Pre-menopausal	91		77%
Post-menopausal	27		23%
Missing	3
1st degree relatives with breast cancer
No	81		91%
Yes	8		9%
Missing	32

^a ≥12 [ever] and < 12 [never] beverages over the course of a lifetime

^bEver smoked >= 100 and Never < 100 cigarettes over the course of your lifetime.