Table 4. Association between lifetime alcohol consumption, drinking at different age intervals, and breast cancer risk among AA women in WCHS.

			OR1		OR2
	Cases (n)	Controls (n)	Estimate	95% CI	Estimate	95% CI
Lifetime alcohol intake
Never	537	568	Ref		Ref
Ever	266	320	0.99	0.80–1.23	0.96	0.78–1.19
Non-drinkera	537	568	Ref		Ref
⩽3510 drinks	150	158	1.14	0.87–1.48	1.11	0.85–1.45
>3510 drinks	107	156	0.81	0.61–1.08	0.77	0.58–1.03
Drinking during <20 years
No	728	760	Ref		Ref
Yes	75	127	0.68	0.50–0.94	0.65	0.47–0.89
Drinking during 20–29 years
No	597	634	Ref		Ref
Yes	206	254	0.98	0.78–1.23	0.94	0.75–1.19
Drinking during 30–39 years
No	595	627	Ref		Ref
Yes	197	245	0.94	0.74–1.18	0.91	0.72–1.15
Drinking during 40–49 years
No	559	582	Ref		Ref
Yes	141	159	1.02	0.78–1.33	0.99	0.76–1.30
Drinking during 50–59 years
No	390	388	Ref		Ref
Yes	72	79	1.02	0.70–1.47	1.00	0.69–1.45
Drinking during ⩾60 years
No	162	130	Ref		Ref
Yes	10	17	0.44	0.18–1.06	0.42	0.17–1.01

Abbreviations: AA= African-American; BMI=body mass index; CI=confidence interval; HRT= hormone replacement therapy; OC=oral contraceptive; OR=odds ratio; WCHS=Women's Circle of Health Study.

OR1: adjusted for age, ethnicity, country of origin, education, age at menarche, parity, age at first birth, breastfeeding status, menopausal status, family history of breast cancer, HRT use, OC use, history of benign breast disease.

OR2: further adjusted for total energy intake and BMI.

^aFifteen women had missing data for number of drinks consumed.