Table 1.

Age-standardized Baseline Characteristics According to Individual Educational Level and Neighborhood Socioeconomic Status Score, Black Women's Health Study, 1995

	Education				Socioeconomic Status Score
Characteristic	≤12 Years		≥16 Years		Quintile 1 (Low)		Quintile 5 (High)
	Mean	%	Mean	%	Mean	%	Mean	%
Age, years	41.9		38.5		39.1		39.4
Age at menarche, years	12.4		12.3		12.4		12.3
Body mass index at age 18 yearsa	21.7		21.3		22.1		20.9
Body mass index at baseline	29.0		27.2		29.4		26.5
Geographic regionb
Northeast		30.6		27.8		26.7		25.7
South		31.6		31.3		30.1		25.6
Midwest		22.7		23.1		32.8		21.0
West		15.1		17.8		10.5		27.6
Mammogram within previous 2 years		78.5		84.1		76.7		84.8
Family history of breast cancer		6.5		6.5		6.7		6.4
Nulliparous		20.4		46.6		27.3		43.6
Parity ≥3		31.2		12.6		27.6		13.8
Age at first birth ≤20 years among parous		53.2		18.9		45.0		22.9
Ever breastfed among parous		27.1		50.7		32.0		51.5
Ever oral contraceptive use		70.5		78.0		72.1		78.7
Ever menopausal female hormone use		15.6		14.8		15.5		15.6
Vigorous exercise ≥5 hours/week		10.8		14.5		11.3		16.0
Alcohol consumption ≥4 drinks/week		15.9		10.3		13.8		12.6
Education ≤12 years						32.4		8.1
Education ≥16 years						27.1		64.9

^a Body mass index: weight (kg)/height (m)².

^b All percents are column percents.