Table 1.

Study Population Characteristics by Total Physical Activity Level, Study of Women's Health Across the Nation, 1996–2004

Characteristicsa	Total Physical Activity Levelb			P Valuec
	Low (0.0–7.0) (n = 225)	Medium (7.1–8.5) (n = 244)	High (8.6–15) (n = 253)
Age, %
40–44 years	27	30	31
45–49 years	56	56	52
50–55 years	17	14	17	0.70
Body mass index, %
<18.5 kg/m2	2	1	2
18.5–24.9 kg/m2	52	55	64
25.0–29.9 kg/m2	24	25	23
≥30 kg/m2	23	19	10	0.01
Race/ethnicity, %
Non-Hispanic whites	41	46	60
African American	7	7	5
Chinese	31	24	17
Japanese	20	23	19	<0.01
Parity, %
Nulliparous	20	19	16
1–2	57	61	57
≥3	23	19	27	0.27
Menopausal status, %
Premenopausal	51	51	57
Early perimenopausal	49	49	43	0.36
Education, %
High school or less	20	20	9
Some college	31	30	26
College or more	49	50	64	<0.01
Smoking status, %
Never	71	72	63
Former	20	21	27
Current	9	8	10	0.20

Abbreviation: SWAN, Study of Women's Health Across the Nation.

^aMenopausal status and body mass index were based on data from the SWAN visit closest to the index mammogram. Age was based on the date of the index mammogram. Other variables were from the baseline SWAN visit.

^bCutoffs represent tertiles on a 1–15 scale based on the distribution among all women. Percentages may not add to 100, because of rounding. There were missing values for parity (n = 1) and smoking status (n = 1).

^cP value from χ² test.