Table 3.

Baseline Characteristics of Study Participants, by Incident Colorectal Cancer Status, Women's Health Initiative, 1994–1998

Characteristic	Incident Colorectal Cancer (n = 1,373)			No Incident Colorectal Cancer(n = 83,335)			P Value
	Mean (SD)	No.a	%	Mean (SD)	No.a	%
Age, years	66.1 (7.0)			63.3 (7.3)			<0.001
BMIb	27.9 (5.8)			27.2 (5.8)			<0.001
Age at menopause, years	47.8 (6.7)			47.4 (6.6)			0.06
Resting pulse (30 seconds)	35.1 (6.6)			34.7 (6.1)			0.02
Ethnicity							<0.01
Non-Hispanic white		1,171	85.4		69,332	83.4
Black		122	8.9		6,786	8.2
Hispanic/Latino		32	2.3		3,220	3.9
Other		46	3.4		3,760	4.5
Educational level							0.07
<College degree		820	60.0		47,633	57.6
≥College degree		546	40.0		35,029	42.4
Income							<0.001
<$20,000		235	18.3		12,126	15.7
$20,000–$49,999		623	48.5		33,275	43.1
$50,000–$74,999		229	17.8		15,765	20.4
≥$75,000		197	15.3		16,119	20.9
Marital status							<0.001
Never married		69	5.0		3,894	4.7
Divorced/separated		216	15.8		13,140	15.8
Widowed		297	21.7		14,082	17.0
Married/living such		787	57.5		51,817	62.5
Smoking status							0.04
Never smoker		652	48.1		42,102	51.2
Past smoker		602	44.4		35,037	42.6
Current smoker		101	7.5		5,173	6.3
Physical activity level							<0.01
No activity		219	16.1		11,095	13.4
Mild		540	39.7		31,553	38.2
Moderate		250	18.4		15,311	18.5
Strenuous		353	25.9		24,628	29.8
Age at menarche, years							0.19
≤10		109	8.0		5,432	6.5
11–13		946	69.0		58,768	70.7
14–15		261	19.0		15,570	18.7
≥16		55	4.0		3,366	4.1
Age at first birth, years							0.82
No term pregnancy		178	14.3		10,634	14.2
<20		153	12.3		9,351	12.4
20–29		797	64.1		48,768	64.9
≥30		115	9.3		6,403	8.5
Parity							0.03
No term pregnancy		178	13.0		10,634	12.8
1		129	9.4		7,589	9.2
2–3		642	47.0		42,008	50.7
≥4		418	30.6		22,660	27.3
Hormone therapy use							<0.001
Never		674	49.2		33,616	40.4
Past		226	16.5		12,217	14.7
Current		471	34.4		37,428	45.0
Hysterectomy							0.52
No		794	57.8		48,869	58.7
Yes		579	42.2		34,390	41.3
Hypertension							0.01
Nonhypertensive		862	63.7		55,459	67.5
Untreated		111	8.2		6,400	7.8
Treated		381	28.1		20,355	24.8
Diabetes (treated)							0.01
No		1,298	94.6		79,857	96.0
Yes		74	5.4		3,374	4.1
High cholesterol requiring medication							0.08
No		1,130	83.6		69,799	85.3
Yes		222	16.4		12,068	14.7
History of CVD							0.01
No		1,220	88.9		75,173	90.9
Yes		153	11.1		7,622	9.2
History of CHF							0.58
No		1,363	99.3		82,606	99.1
Yes		10	0.7		724	0.9
Warfarin use							0.58
No		1,355	98.7		82,376	98.9
Yes		18	1.3		958	1.2
Anti-arrhythmic use							0.48
No		1,369	99.7		82,989	99.6
Yes		4	0.3		345	0.4
Aspirin use							0.31
No		1,074	78.2		64,221	77.1
Yes		299	21.8		19,113	22.9
Statin use							0.83
No		1,264	92.1		76,589	91.9
Yes		109	7.9		6,745	8.1
β-blocker use							0.83
No		1,257	91.6		76,427	91.7
Yes		116	8.5		6,908	8.3
Calcium channel blocker use							0.33
No		1,230	89.6		75,306	90.4
Yes		143	10.4		8,029	9.6
ACE inhibitor use							0.98
No		1,265	92.1		76,794	92.2
Yes		108	7.9		6,541	7.9
Angiotensin II receptor blocker use							0.56
No		1,361	99.1		82,720	99.3
Yes		12	0.9		615	0.7
Cardiac glycoside use							0.40
No		1,341	97.7		81,662	98.0
Yes		32	2.3		1,672	2.0

Abbreviations: ACE, angiotensin-converting enzyme; BMI, body mass index; CHF, congestive heart failure; CVD, cardiovascular disease; SD, standard deviation.

^a Subgroup totals may not sum to the column total because of missing data.

^b Weight (kg)/height (m)².